diff --git a/less/carousel.less b/less/carousel.less
index a28e397a551d8569fd9fc1f3e86d75ded2e27b56..4bbe946d3aa8f36a49c9dd77306e02888634be87 100644
--- a/less/carousel.less
+++ b/less/carousel.less
@@ -196,6 +196,7 @@
     // Internet Explorer 8-9 does not support clicks on elements without a set
     // `background-color`. We cannot use `filter` since that's not viewed as a
     // background color by the browser. Thus, a hack is needed.
+    // See https://developer.mozilla.org/en-US/docs/Web/Events/click#Internet_Explorer
     //
     // For IE8, we set solid black as it doesn't support `rgba()`. For IE9, we
     // set alpha transparency for the best results possible.
diff --git a/less/close.less b/less/close.less
index 9b4e74f2b82f8fb183bdd9a5a5ddae4ec29deb92..6d5bfe087aed3342270b1de9d70d034c474a3779 100644
--- a/less/close.less
+++ b/less/close.less
@@ -23,6 +23,7 @@
   // Additional properties for button version
   // iOS requires the button element instead of an anchor tag.
   // If you want the anchor version, it requires `href="#"`.
+  // See https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile
   button& {
     padding: 0;
     cursor: pointer;
diff --git a/less/forms.less b/less/forms.less
index f37d1c8f8f67877d47c7604a709e107a90dba245..d1e29b118328671475aba3006ebede6bf84f684f 100644
--- a/less/forms.less
+++ b/less/forms.less
@@ -143,7 +143,7 @@ output {
   fieldset[disabled] & {
     cursor: @cursor-disabled;
     background-color: @input-bg-disabled;
-    opacity: 1; // iOS fix for unreadable disabled content
+    opacity: 1; // iOS fix for unreadable disabled content; see https://github.com/twbs/bootstrap/issues/11655
   }
 
   // Reset height for `textarea`s
diff --git a/less/theme.less b/less/theme.less
index a15d16ecd2d2c1167c1027d6fa26485f3c592ad7..3673accc0999596e2d285f2adacce602146345fa 100644
--- a/less/theme.less
+++ b/less/theme.less
@@ -36,7 +36,7 @@
 // Mixin for generating new styles
 .btn-styles(@btn-color: #555) {
   #gradient > .vertical(@start-color: @btn-color; @end-color: darken(@btn-color, 12%));
-  .reset-filter(); // Disable gradients for IE9 because filter bleeds through rounded corners
+  .reset-filter(); // Disable gradients for IE9 because filter bleeds through rounded corners; see https://github.com/twbs/bootstrap/issues/10620
   background-repeat: repeat-x;
   border-color: darken(@btn-color, 14%);
 
@@ -130,7 +130,7 @@
 // Inverted navbar
 .navbar-inverse {
   #gradient > .vertical(@start-color: lighten(@navbar-inverse-bg, 10%); @end-color: @navbar-inverse-bg);
-  .reset-filter(); // Remove gradient in IE<10 to fix bug where dropdowns don't get triggered
+  .reset-filter(); // Remove gradient in IE<10 to fix bug where dropdowns don't get triggered; see https://github.com/twbs/bootstrap/issues/10257
 
   .navbar-nav > .open > a,
   .navbar-nav > .active > a {