Glyphicons are a font family of 260 icons from the Glyphicon Halflings set. Normally these icons are not available for free, but the creator has made them available to Bootstrap customers for free.
Many thanks to the providers of Glyphicons
Listing 10.6 - A Glyphicon Inline in Text
aria-hidden="true"attribute. Listing 10.7 shows how.
Listing 10.7 - Icon hidden from Assistive Devices
Listing 10.8 - Icon with Meaning
Icon courtesy Glyphicons.