diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
index be762f4a0fd..2501475d735 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
@@ -14,6 +14,6 @@ interface CSSStyleDeclaration {
     [CEReactions] CSSOMString removeProperty(CSSOMString property);
 
     [FIXME] readonly attribute CSSRule? parentRule;
-    // FIXME: [CEReactions] attribute [LegacyNullToEmptyString] CSSOMString cssFloat;
+    [FIXME, CEReactions, LegacyNullToEmptyString] attribute CSSOMString cssFloat;
 
 };
diff --git a/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl b/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
index 55d0aee8921..30e13c4d5b4 100644
--- a/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
+++ b/Userland/Libraries/LibWeb/CSS/FontFaceSet.idl
@@ -24,9 +24,9 @@ interface FontFaceSet : EventTarget {
     [FIXME] undefined clear();
 
     // events for when loading state changes
-    // FIXME: attribute EventHandler onloading;
-    // FIXME: attribute EventHandler onloadingdone;
-    // FIXME: attribute EventHandler onloadingerror;
+    [FIXME] attribute EventHandler onloading;
+    [FIXME] attribute EventHandler onloadingdone;
+    [FIXME] attribute EventHandler onloadingerror;
 
     // check and start loads if appropriate
     // and fulfill promise when all loads complete
diff --git a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasCompositing.idl b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasCompositing.idl
index 413d3c8d564..c67ed293e81 100644
--- a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasCompositing.idl
+++ b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasCompositing.idl
@@ -2,5 +2,5 @@
 interface mixin CanvasCompositing {
     // compositing
     attribute unrestricted double globalAlpha; // (default 1.0)
-    // FIXME:  attribute DOMString globalCompositeOperation; // (default "source-over")
+    [FIXME] attribute DOMString globalCompositeOperation; // (default "source-over")
 };
diff --git a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasPathDrawingStyles.idl b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasPathDrawingStyles.idl
index 648bb2afda5..85f16378989 100644
--- a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasPathDrawingStyles.idl
+++ b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasPathDrawingStyles.idl
@@ -5,11 +5,11 @@ enum CanvasLineJoin { "round", "bevel", "miter" };
 // https://html.spec.whatwg.org/multipage/canvas.html#canvaspathdrawingstyles
 interface mixin CanvasPathDrawingStyles {
     attribute unrestricted double lineWidth;
-    // FIXME: attribute CanvasLineCap lineCap;
-    // FIXME: attribute CanvasLineJoin lineJoin;
-    // FIXME: attribute unrestricted double miterLimit;
+    [FIXME] attribute CanvasLineCap lineCap;
+    [FIXME] attribute CanvasLineJoin lineJoin;
+    [FIXME] attribute unrestricted double miterLimit;
 
     [FIXME] undefined setLineDash(sequence<unrestricted double> segments);
     [FIXME] sequence<unrestricted double> getLineDash();
-    // FIXME: attribute unrestricted double lineDashOffset;
+    [FIXME] attribute unrestricted double lineDashOffset;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.idl b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.idl
index c1273c82d95..0c1abaed092 100644
--- a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.idl
+++ b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.idl
@@ -14,11 +14,11 @@ interface mixin CanvasTextDrawingStyles {
     attribute DOMString font; // (default 10px sans-serif)
     attribute CanvasTextAlign textAlign; // (default: "start")
     attribute CanvasTextBaseline textBaseline; // (default: "alphabetic")
-    // FIXME: attribute CanvasDirection direction; // (default: "inherit")
-    // FIXME: attribute DOMString letterSpacing; // (default: "0px")
-    // FIXME: attribute CanvasFontKerning fontKerning; // (default: "auto")
-    // FIXME: attribute CanvasFontStretch fontStretch; // (default: "normal")
-    // FIXME: attribute CanvasFontVariantCaps fontVariantCaps; // (default: "normal")
-    // FIXME: attribute CanvasTextRendering textRendering; // (default: "auto")
-    // FIXME: attribute DOMString wordSpacing; // (default: "0px")
+    [FIXME] attribute CanvasDirection direction; // (default: "inherit")
+    [FIXME] attribute DOMString letterSpacing; // (default: "0px")
+    [FIXME] attribute CanvasFontKerning fontKerning; // (default: "auto")
+    [FIXME] attribute CanvasFontStretch fontStretch; // (default: "normal")
+    [FIXME] attribute CanvasFontVariantCaps fontVariantCaps; // (default: "normal")
+    [FIXME] attribute CanvasTextRendering textRendering; // (default: "auto")
+    [FIXME] attribute DOMString wordSpacing; // (default: "0px")
 };
diff --git a/Userland/Libraries/LibWeb/HTML/DataTransfer.idl b/Userland/Libraries/LibWeb/HTML/DataTransfer.idl
index 2c0710a53be..eb43f4487a1 100644
--- a/Userland/Libraries/LibWeb/HTML/DataTransfer.idl
+++ b/Userland/Libraries/LibWeb/HTML/DataTransfer.idl
@@ -3,8 +3,8 @@
 interface DataTransfer {
     constructor();
 
-    // FIXME: attribute DOMString dropEffect;
-    // FIXME: attribute DOMString effectAllowed;
+    [FIXME] attribute DOMString dropEffect;
+    [FIXME] attribute DOMString effectAllowed;
 
     [FIXME, SameObject] readonly attribute DataTransferItemList items;
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLAreaElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLAreaElement.idl
index a37a4e65579..fb17dd0815d 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLAreaElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLAreaElement.idl
@@ -15,7 +15,7 @@ interface HTMLAreaElement : HTMLElement {
     [CEReactions, Reflect] attribute USVString ping;
     [CEReactions, Reflect] attribute DOMString rel;
     [SameObject, PutForwards=value] readonly attribute DOMTokenList relList;
-    // FIXME: [CEReactions] attribute DOMString referrerPolicy;
+    [FIXME, CEReactions] attribute DOMString referrerPolicy;
 
     // Obsolete
     [Reflect=nohref] attribute boolean noHref;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLElement.idl
index 5b2086a9133..8c02b61a7e9 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLElement.idl
@@ -12,7 +12,7 @@ interface HTMLElement : Element {
     // metadata attributes
     [Reflect, CEReactions] attribute DOMString title;
     [Reflect, CEReactions] attribute DOMString lang;
-    // FIXME: [CEReactions] attribute boolean translate;
+    [FIXME, CEReactions] attribute boolean translate;
     [CEReactions] attribute DOMString dir;
 
     // user interaction
@@ -21,9 +21,9 @@ interface HTMLElement : Element {
     undefined click();
     [Reflect=accesskey, CEReactions] attribute DOMString accessKey;
     readonly attribute DOMString accessKeyLabel;
-    // FIXME: [CEReactions] attribute boolean draggable;
-    // FIXME: [CEReactions] attribute boolean spellcheck;
-    // FIXME: [CEReactions] attribute DOMString autocapitalize;
+    [FIXME, CEReactions] attribute boolean draggable;
+    [FIXME, CEReactions] attribute boolean spellcheck;
+    [FIXME, CEReactions] attribute DOMString autocapitalize;
 
     [LegacyNullToEmptyString, CEReactions] attribute DOMString innerText;
     [LegacyNullToEmptyString, CEReactions] attribute DOMString outerText;
@@ -34,7 +34,7 @@ interface HTMLElement : Element {
     [FIXME] undefined showPopover();
     [FIXME] undefined hidePopover();
     [FIXME] boolean togglePopover(optional boolean force);
-    // FIXME: [CEReactions] attribute DOMString? popover;
+    [FIXME, CEReactions] attribute DOMString? popover;
 
     // https://drafts.csswg.org/cssom-view/#extensions-to-the-htmlelement-interface
     readonly attribute Element? offsetParent;
@@ -52,15 +52,15 @@ HTMLElement includes HTMLOrSVGElement;
 // https://html.spec.whatwg.org/#elementcontenteditable
 interface mixin ElementContentEditable {
     [CEReactions] attribute DOMString contentEditable;
-    // FIXME: [CEReactions] attribute DOMString enterKeyHint;
+    [FIXME, CEReactions] attribute DOMString enterKeyHint;
     readonly attribute boolean isContentEditable;
-    // FIXME: [CEReactions] attribute DOMString inputMode;
+    [FIXME, CEReactions] attribute DOMString inputMode;
 };
 
 // https://html.spec.whatwg.org/#htmlorsvgelement
 interface mixin HTMLOrSVGElement {
     [SameObject] readonly attribute DOMStringMap dataset;
-    // FIXME: attribute DOMString nonce; // intentionally no [CEReactions]
+    [FIXME] attribute DOMString nonce; // intentionally no [CEReactions]
 
     [CEReactions, Reflect] attribute boolean autofocus;
     [CEReactions] attribute long tabIndex;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.idl
index e4b513aebc4..baef3669f7a 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.idl
@@ -9,9 +9,9 @@ interface HTMLFormElement : HTMLElement {
 
     [CEReactions, Reflect=accept-charset] attribute DOMString acceptCharset;
     [CEReactions] attribute USVString action;
-    // FIXME: [CEReactions] attribute DOMString autocomplete;
-    // FIXME: [CEReactions] attribute DOMString enctype;
-    // FIXME: [CEReactions] attribute DOMString encoding;
+    [FIXME, CEReactions] attribute DOMString autocomplete;
+    [FIXME, CEReactions] attribute DOMString enctype;
+    [FIXME, CEReactions] attribute DOMString encoding;
     [CEReactions] attribute DOMString method;
     [CEReactions, Reflect] attribute DOMString name;
     [CEReactions, Reflect=novalidate] attribute boolean noValidate;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFrameElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLFrameElement.idl
index c9d54fd5863..9b2cd85c780 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFrameElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFrameElement.idl
@@ -11,11 +11,11 @@ interface HTMLFrameElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString src;
     [CEReactions, Reflect=frameborder] attribute DOMString frameBorder;
     [CEReactions, Reflect=longdesc] attribute DOMString longDesc;
-    // FIXME: [CEReactions] attribute boolean noResize;
+    [FIXME, CEReactions] attribute boolean noResize;
     [FIXME] readonly attribute Document? contentDocument;
     [FIXME] readonly attribute WindowProxy? contentWindow;
 
-    // FIXME: [CEReactions] attribute [LegacyNullToEmptyString] DOMString marginHeight;
-    // FIXME: [CEReactions] attribute [LegacyNullToEmptyString] DOMString marginWidth;
+    [FIXME, CEReactions, LegacyNullToEmptyString] attribute DOMString marginHeight;
+    [FIXME, CEReactions, LegacyNullToEmptyString] attribute DOMString marginWidth;
 
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.idl
index 3d4cae878de..bc758befeba 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.idl
@@ -10,13 +10,13 @@ interface HTMLIFrameElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString src;
     [CEReactions, Reflect] attribute DOMString srcdoc;
     [CEReactions, Reflect] attribute DOMString name;
-    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList sandbox;
+    [FIXME, SameObject, PutForwards=value] readonly attribute DOMTokenList sandbox;
     [CEReactions, Reflect] attribute DOMString allow;
     [CEReactions, Reflect=allowfullscreen] attribute boolean allowFullscreen;
     [CEReactions, Reflect] attribute DOMString width;
     [CEReactions, Reflect] attribute DOMString height;
-    // FIXME: [CEReactions] attribute DOMString referrerPolicy;
-    // FIXME: [CEReactions] attribute DOMString loading;
+    [FIXME, CEReactions] attribute DOMString referrerPolicy;
+    [FIXME, CEReactions] attribute DOMString loading;
     readonly attribute Document? contentDocument;
     readonly attribute WindowProxy? contentWindow;
     Document? getSVGDocument();
@@ -25,7 +25,7 @@ interface HTMLIFrameElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString align;
     [CEReactions, Reflect] attribute DOMString scrolling;
     [CEReactions, Reflect=frameborder] attribute DOMString frameBorder;
-    // FIXME: [CEReactions] attribute USVString longDesc;
+    [FIXME, CEReactions] attribute USVString longDesc;
 
     [CEReactions, LegacyNullToEmptyString, Reflect=marginheight] attribute DOMString marginHeight;
     [CEReactions, LegacyNullToEmptyString, Reflect=marginwidth] attribute DOMString marginWidth;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLImageElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLImageElement.idl
index da30c723985..e7ba271cf99 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLImageElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLImageElement.idl
@@ -10,7 +10,7 @@ interface HTMLImageElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString src;
     [CEReactions, Reflect] attribute DOMString srcset;
     [CEReactions, Reflect] attribute DOMString sizes;
-    // FIXME: [CEReactions] attribute DOMString? crossOrigin;
+    [FIXME, CEReactions] attribute DOMString? crossOrigin;
     [CEReactions, Reflect=usemap] attribute DOMString useMap;
     [CEReactions, Reflect=ismap] attribute boolean isMap;
     [CEReactions] attribute unsigned long width;
@@ -19,20 +19,20 @@ interface HTMLImageElement : HTMLElement {
     readonly attribute unsigned long naturalHeight;
     readonly attribute boolean complete;
     [FIXME] readonly attribute USVString currentSrc;
-    // FIXME: [CEReactions] attribute DOMString referrerPolicy;
-    // FIXME: [CEReactions] attribute DOMString decoding;
-    // FIXME: [CEReactions] attribute DOMString loading;
-    // FIXME: [CEReactions] attribute DOMString fetchPriority;
+    [FIXME, CEReactions] attribute DOMString referrerPolicy;
+    [FIXME, CEReactions] attribute DOMString decoding;
+    [FIXME, CEReactions] attribute DOMString loading;
+    [FIXME, CEReactions] attribute DOMString fetchPriority;
 
     [FIXME] Promise<undefined> decode();
 
     // Obsolete
     [CEReactions, Reflect] attribute DOMString name;
-    // FIXME: [CEReactions] attribute USVString lowsrc;
+    [FIXME, CEReactions] attribute USVString lowsrc;
     [CEReactions, Reflect] attribute DOMString align;
-    // FIXME: [CEReactions] attribute unsigned long hspace;
-    // FIXME: [CEReactions] attribute unsigned long vspace;
-    // FIXME: [CEReactions] attribute USVString longDesc;
+    [FIXME, CEReactions] attribute unsigned long hspace;
+    [FIXME, CEReactions] attribute unsigned long vspace;
+    [FIXME, CEReactions] attribute USVString longDesc;
 
     [CEReactions, LegacyNullToEmptyString, Reflect] attribute DOMString border;
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
index f9c5e76b385..654c218cd56 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
@@ -9,19 +9,19 @@ interface HTMLInputElement : HTMLElement {
 
     [CEReactions, Reflect] attribute DOMString accept;
     [CEReactions, Reflect] attribute DOMString alt;
-    // FIXME: [CEReactions] attribute DOMString autocomplete;
+    [FIXME, CEReactions] attribute DOMString autocomplete;
     [CEReactions, Reflect=checked] attribute boolean defaultChecked;
     [ImplementedAs=checked_binding] attribute boolean checked;
     [CEReactions, Reflect=dirname] attribute DOMString dirName;
     [CEReactions, Reflect] attribute boolean disabled;
     readonly attribute HTMLFormElement? form;
     attribute FileList? files;
-    // FIXME: [CEReactions] attribute USVString formAction;
-    // FIXME: [CEReactions] attribute DOMString formEnctype;
-    // FIXME: [CEReactions] attribute DOMString formMethod;
+    [FIXME, CEReactions] attribute USVString formAction;
+    [FIXME, CEReactions] attribute DOMString formEnctype;
+    [FIXME, CEReactions] attribute DOMString formMethod;
     [CEReactions, Reflect=formnovalidate] attribute boolean formNoValidate;
     [CEReactions, Reflect=formtarget] attribute DOMString formTarget;
-    // FIXME: [CEReactions] attribute unsigned long height;
+    [FIXME, CEReactions] attribute unsigned long height;
     attribute boolean indeterminate;
     [FIXME] readonly attribute HTMLDataListElement? list;
     [CEReactions, Reflect] attribute DOMString max;
@@ -30,7 +30,7 @@ interface HTMLInputElement : HTMLElement {
     [CEReactions] attribute long minLength;
     [CEReactions, Reflect] attribute boolean multiple;
     [CEReactions, Reflect] attribute DOMString name;
-    // FIXME: [CEReactions] attribute DOMString pattern;
+    [FIXME, CEReactions] attribute DOMString pattern;
     [CEReactions, Reflect] attribute DOMString placeholder;
     [CEReactions, Reflect=readonly] attribute boolean readOnly;
     [CEReactions, Reflect] attribute boolean required;
@@ -42,7 +42,7 @@ interface HTMLInputElement : HTMLElement {
     [CEReactions, LegacyNullToEmptyString] attribute DOMString value;
     attribute object? valueAsDate;
     attribute unrestricted double valueAsNumber;
-    // FIXME: [CEReactions] attribute unsigned long width;
+    [FIXME, CEReactions] attribute unsigned long width;
 
     undefined stepUp(optional long n = 1);
     undefined stepDown(optional long n = 1);
@@ -57,9 +57,9 @@ interface HTMLInputElement : HTMLElement {
     readonly attribute NodeList? labels;
 
     undefined select();
-    // FIXME: attribute unsigned long? selectionStart;
-    // FIXME: attribute unsigned long? selectionEnd;
-    // FIXME: attribute DOMString? selectionDirection;
+    [FIXME] attribute unsigned long? selectionStart;
+    [FIXME] attribute unsigned long? selectionEnd;
+    [FIXME] attribute DOMString? selectionDirection;
     [FIXME] undefined setRangeText(DOMString replacement);
     [FIXME] undefined setRangeText(DOMString replacement, unsigned long start, unsigned long end, optional SelectionMode selectionMode = "preserve");
     undefined setSelectionRange(unsigned long start, unsigned long end, optional DOMString direction);
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.idl
index fb685810b08..c3b62a5633a 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.idl
@@ -8,21 +8,21 @@ interface HTMLLinkElement : HTMLElement {
     [HTMLConstructor] constructor();
 
     [CEReactions, Reflect] attribute DOMString href;
-    // FIXME: [CEReactions] attribute DOMString? crossOrigin;
+    [FIXME, CEReactions] attribute DOMString? crossOrigin;
     [CEReactions, Reflect] attribute DOMString rel;
-    // FIXME: [CEReactions] attribute DOMString as;
+    [FIXME, CEReactions] attribute DOMString as;
     [SameObject, PutForwards=value] readonly attribute DOMTokenList relList;
     [CEReactions, Reflect] attribute DOMString media;
     [CEReactions, Reflect] attribute DOMString integrity;
     [CEReactions, Reflect] attribute DOMString hreflang;
     [CEReactions, Reflect] attribute DOMString type;
-    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList sizes;
+    [FIXME, SameObject, PutForwards=value] readonly attribute DOMTokenList sizes;
     [CEReactions, Reflect=imagesrcset] attribute DOMString imageSrcset;
     [CEReactions, Reflect=imagesizes] attribute DOMString imageSizes;
-    // FIXME: [CEReactions] attribute DOMString referrerPolicy;
-    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
+    [FIXME, CEReactions] attribute DOMString referrerPolicy;
+    [FIXME, SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
     [CEReactions, Reflect] attribute boolean disabled;
-    // FIXME: [CEReactions] attribute DOMString fetchPriority;
+    [FIXME, CEReactions] attribute DOMString fetchPriority;
 
     // Obsolete
     [CEReactions, Reflect] attribute DOMString charset;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMarqueeElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLMarqueeElement.idl
index 45c6f0a787b..fbd9739267c 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMarqueeElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMarqueeElement.idl
@@ -10,12 +10,12 @@ interface HTMLMarqueeElement : HTMLElement {
     [CEReactions, Reflect=bgcolor] attribute DOMString bgColor;
     [CEReactions, Reflect] attribute DOMString direction;
     [CEReactions, Reflect] attribute DOMString height;
-    // FIXME: [CEReactions] attribute unsigned long hspace;
-    // FIXME: [CEReactions] attribute long loop;
-    // FIXME: [CEReactions] attribute unsigned long scrollAmount;
-    // FIXME: [CEReactions] attribute unsigned long scrollDelay;
-    // FIXME: [CEReactions] attribute boolean trueSpeed;
-    // FIXME: [CEReactions] attribute unsigned long vspace;
+    [FIXME, CEReactions] attribute unsigned long hspace;
+    [FIXME, CEReactions] attribute long loop;
+    [FIXME, CEReactions] attribute unsigned long scrollAmount;
+    [FIXME, CEReactions] attribute unsigned long scrollDelay;
+    [FIXME, CEReactions] attribute boolean trueSpeed;
+    [FIXME, CEReactions] attribute unsigned long vspace;
     [CEReactions, Reflect] attribute DOMString width;
 
     [FIXME] undefined start();
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.idl
index 26d4a2f3230..74c5e67d9d6 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.idl
@@ -20,7 +20,7 @@ interface HTMLMediaElement : HTMLElement {
 
     // network state
     [Reflect, CEReactions] attribute DOMString src;
-    // FIXME: attribute MediaProvider? srcObject;
+    [FIXME] attribute MediaProvider? srcObject;
     readonly attribute USVString currentSrc;
     [Reflect=crossorigin, CEReactions, Enumerated=CORSSettingsAttribute] attribute DOMString? crossOrigin;
     const unsigned short NETWORK_EMPTY = 0;
@@ -28,7 +28,7 @@ interface HTMLMediaElement : HTMLElement {
     const unsigned short NETWORK_LOADING = 2;
     const unsigned short NETWORK_NO_SOURCE = 3;
     readonly attribute unsigned short networkState;
-    // FIXME: [CEReactions] attribute DOMString preload;
+    [FIXME, CEReactions] attribute DOMString preload;
     readonly attribute TimeRanges buffered;
     undefined load();
     CanPlayTypeResult canPlayType(DOMString type);
@@ -48,9 +48,9 @@ interface HTMLMediaElement : HTMLElement {
     readonly attribute unrestricted double duration;
     // FIXME: object getStartDate();
     readonly attribute boolean paused;
-    // FIXME: attribute double defaultPlaybackRate;
-    // FIXME: attribute double playbackRate;
-    // FIXME: attribute boolean preservesPitch;
+    [FIXME] attribute double defaultPlaybackRate;
+    [FIXME] attribute double playbackRate;
+    [FIXME] attribute boolean preservesPitch;
     [FIXME] readonly attribute TimeRanges played;
     [FIXME] readonly attribute TimeRanges seekable;
     readonly attribute boolean ended;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.idl
index dc9c146ff15..ee1ab9ec6ab 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.idl
@@ -29,10 +29,10 @@ interface HTMLObjectElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString archive;
     [CEReactions, Reflect] attribute DOMString code;
     [CEReactions, Reflect] attribute boolean declare;
-    // FIXME: [CEReactions] attribute unsigned long hspace;
+    [FIXME, CEReactions] attribute unsigned long hspace;
     [CEReactions, Reflect] attribute DOMString standby;
-    // FIXME: [CEReactions] attribute unsigned long vspace;
-    // FIXME: [CEReactions] attribute DOMString codeBase;
+    [FIXME, CEReactions] attribute unsigned long vspace;
+    [FIXME, CEReactions] attribute DOMString codeBase;
     [CEReactions, Reflect=codetype] attribute DOMString codeType;
     [CEReactions, Reflect=usemap] attribute DOMString useMap;
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.idl
index c4ac9c81080..b57c031664b 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.idl
@@ -16,8 +16,8 @@ interface HTMLScriptElement : HTMLElement {
     [CEReactions] attribute DOMString text;
     [CEReactions, Reflect] attribute DOMString integrity;
     [CEReactions, Reflect=referrerpolicy] attribute DOMString referrerPolicy;
-    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
-    // FIXME: [CEReactions] attribute DOMString fetchPriority;
+    [FIXME, SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
+    [FIXME, CEReactions] attribute DOMString fetchPriority;
 
     static boolean supports(DOMString type);
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLSourceElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLSourceElement.idl
index 49aeb6d57a6..19116eab585 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLSourceElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLSourceElement.idl
@@ -11,7 +11,7 @@ interface HTMLSourceElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString srcset;
     [CEReactions, Reflect] attribute DOMString sizes;
     [CEReactions, Reflect] attribute DOMString media;
-    // FIXME: [CEReactions, Reflect] attribute unsigned long width;
-    // FIXME: [CEReactions, Reflect] attribute unsigned long height;
+    [FIXME, CEReactions, Reflect] attribute unsigned long width;
+    [FIXME, CEReactions, Reflect] attribute unsigned long height;
 
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLStyleElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLStyleElement.idl
index 600459b4ddf..a6311e7cc2d 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLStyleElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLStyleElement.idl
@@ -7,9 +7,9 @@
 interface HTMLStyleElement : HTMLElement {
     [HTMLConstructor] constructor();
 
-    // FIXME: attribute boolean disabled;
+    [FIXME] attribute boolean disabled;
     [Reflect, CEReactions] attribute DOMString media;
-    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
+    [FIXME, SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
 
     // Obsolete
     [Reflect] attribute DOMString type;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTableCellElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLTableCellElement.idl
index c20dfbe3420..1e84585b399 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTableCellElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTableCellElement.idl
@@ -11,7 +11,7 @@ interface HTMLTableCellElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString headers;
     [FIXME] readonly attribute long cellIndex;
 
-    // FIXME: [CEReactions] attribute DOMString scope; // only conforming for th elements
+    [FIXME, CEReactions] attribute DOMString scope; // only conforming for th elements
     [CEReactions, Reflect] attribute DOMString abbr;  // only conforming for th elements
 
     // Obsolete
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
index ad16d7fd008..af1f183b006 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
@@ -37,7 +37,7 @@ interface HTMLTextAreaElement : HTMLElement {
     // FIXME: undefined select();
     attribute unsigned long selectionStart;
     attribute unsigned long selectionEnd;
-    // FIXME: attribute DOMString selectionDirection;
+    [FIXME] attribute DOMString selectionDirection;
     [FIXME] undefined setRangeText(DOMString replacement);
     [FIXME] undefined setRangeText(DOMString replacement, unsigned long start, unsigned long end, optional SelectionMode selectionMode = "preserve");
     [FIXME] undefined setSelectionRange(unsigned long start, unsigned long end, optional DOMString direction);
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTrackElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLTrackElement.idl
index c1836a1cc96..6d800e28c44 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTrackElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTrackElement.idl
@@ -6,7 +6,7 @@ interface HTMLTrackElement : HTMLElement {
 
     [HTMLConstructor] constructor();
 
-    // FIXME: [CEReactions] attribute DOMString kind;
+    [FIXME, CEReactions] attribute DOMString kind;
     [CEReactions, Reflect] attribute DOMString src;
     [CEReactions, Reflect] attribute DOMString srclang;
     [CEReactions, Reflect] attribute DOMString label;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLVideoElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLVideoElement.idl
index 4d0daf20227..3c8c99659dc 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLVideoElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLVideoElement.idl
@@ -6,8 +6,8 @@ interface HTMLVideoElement : HTMLMediaElement {
 
     [HTMLConstructor] constructor();
 
-    // FIXME: [CEReactions] attribute unsigned long width;
-    // FIXME: [CEReactions] attribute unsigned long height;
+    [FIXME, CEReactions] attribute unsigned long width;
+    [FIXME, CEReactions] attribute unsigned long height;
     readonly attribute unsigned long videoWidth;
     readonly attribute unsigned long videoHeight;
     [CEReactions, Reflect] attribute USVString poster;
diff --git a/Userland/Libraries/LibWeb/IndexedDB/IDBOpenDBRequest.idl b/Userland/Libraries/LibWeb/IndexedDB/IDBOpenDBRequest.idl
index a645029b620..dd1f05cb4fb 100644
--- a/Userland/Libraries/LibWeb/IndexedDB/IDBOpenDBRequest.idl
+++ b/Userland/Libraries/LibWeb/IndexedDB/IDBOpenDBRequest.idl
@@ -4,6 +4,6 @@
 [Exposed=(Window,Worker)]
 interface IDBOpenDBRequest : IDBRequest {
     // Event handlers:
-    // FIXME: attribute EventHandler onblocked;
-    // FIXME: attribute EventHandler onupgradeneeded;
+    [FIXME] attribute EventHandler onblocked;
+    [FIXME] attribute EventHandler onupgradeneeded;
 };
diff --git a/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.idl b/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.idl
index 867f16a5098..dc6b43edf59 100644
--- a/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.idl
+++ b/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.idl
@@ -10,8 +10,8 @@ interface IDBRequest : EventTarget {
     [FIXME] readonly attribute IDBRequestReadyState readyState;
 
     // Event handlers:
-    // FIXME: attribute EventHandler onsuccess;
-    // FIXME: attribute EventHandler onerror;
+    [FIXME] attribute EventHandler onsuccess;
+    [FIXME] attribute EventHandler onerror;
 };
 
 enum IDBRequestReadyState {
diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioNode.idl b/Userland/Libraries/LibWeb/WebAudio/AudioNode.idl
index b602cd8c847..7237dd11f5d 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioNode.idl
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioNode.idl
@@ -40,7 +40,7 @@ interface AudioNode : EventTarget {
     readonly attribute BaseAudioContext context;
     [FIXME] readonly attribute unsigned long numberOfInputs;
     [FIXME] readonly attribute unsigned long numberOfOutputs;
-    // FIXME: attribute unsigned long channelCount;
-    // FIXME: attribute ChannelCountMode channelCountMode;
-    // FIXME: attribute ChannelInterpretation channelInterpretation;
+    [FIXME] attribute unsigned long channelCount;
+    [FIXME] attribute ChannelCountMode channelCountMode;
+    [FIXME] attribute ChannelInterpretation channelInterpretation;
 };
diff --git a/Userland/Libraries/LibWeb/WebAudio/BaseAudioContext.idl b/Userland/Libraries/LibWeb/WebAudio/BaseAudioContext.idl
index a8f7aaa049d..2141dd8140b 100644
--- a/Userland/Libraries/LibWeb/WebAudio/BaseAudioContext.idl
+++ b/Userland/Libraries/LibWeb/WebAudio/BaseAudioContext.idl
@@ -13,7 +13,7 @@ enum AudioContextState { "suspended", "running", "closed" };
 // https://webaudio.github.io/web-audio-api/#BaseAudioContext
 [Exposed=Window]
 interface BaseAudioContext : EventTarget {
-    // FIXME: readonly attribute AudioDestinationNode destination;
+    [FIXME] readonly attribute AudioDestinationNode destination;
     readonly attribute float sampleRate;
     readonly attribute double currentTime;
     [FIXME] readonly attribute AudioListener listener;