Typographic pictograms have a suitable alternative.
The use of web fonts (downloadable character fonts) has considerably facilitated the use of a technical trick very appreciated from a performance point of view: replacing the images of various icons with a graphic UTF-8 character obtained thanks to a font specific, however, carries significant risks, particularly in terms of accessibility, if you do not take care to provide a textual alternative to this character diverted from its default meaning.
Objectives
Improve the accessibility of content to people with disabilities.
Implementation
Test the text containing the character(s) concerned with the sound rendering of the reading software.
If the software does not recognize the character, then we will use content hidden on display via CSS.
Control
Examine the code directly to verify that each icon displayed via a font has, where appropriate, an alternative in the HTML content.