diff -r d4ec02c51c91 -r af15590802a4 assets/stylesheets/bootstrap/mixins/_hide-text.scss
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/assets/stylesheets/bootstrap/mixins/_hide-text.scss	Thu Jun 15 12:17:09 2017 +0200
@@ -0,0 +1,21 @@
+// CSS image replacement
+//
+// Heads up! v3 launched with only `.hide-text()`, but per our pattern for
+// mixins being reused as classes with the same name, this doesn't hold up. As
+// of v3.0.1 we have added `.text-hide()` and deprecated `.hide-text()`.
+//
+// Source: https://github.com/h5bp/html5-boilerplate/commit/aa0396eae757
+
+// Deprecated as of v3.0.1 (will be removed in v4)
+@mixin hide-text() {
+  font: 0/0 a;
+  color: transparent;
+  text-shadow: none;
+  background-color: transparent;
+  border: 0;
+}
+
+// New mixin to use as of v3.0.1
+@mixin text-hide() {
+  @include hide-text;
+}