I'm curious from an accessibility standpoint how the WCAG guideline 1.4.4 (Resize Text) would be interpreted for user interface components, such as buttons, that only use a single symbol or glyph. An example would be an X for a close button, or < and > for image carousel controls.
It is my understanding of the guideline that, excluding captions and images of text, rendered text should be able to be resized up to 200 percent without loss of content or functionality. By that definition, call to action buttons with text such as "Save" or "Apply" would be subject to that guideline as well.
If, however, a button only has a symbol or glyph to denote it, would it be expected to resize as well along with applicable text and if it did not, would it fail 1.4.4? This is assuming the button is a text character and not an image, which would pass the guideline.
The guideline says:
Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.
If you follow the definition of "text" from the guideline, it says:
sequence of characters that can be programmatically determined, where the sequence is expressing something in human language
And then you have to follow the definition of "human language", which says:
language that is spoken, written or signed (through visual or tactile means) to communicate with humans
A "symbol or glyph" is typically not a character that is spoken. You might come up with a word that describes the symbol or glyph but the actual symbol or glyph itself is not spoken. So I would say 1.4.4 does not apply from a conformance perspective.
Note that the actual guideline is "normative" and any definitions contained within the wording of the guideline is normative as well. So the definitions of "text" and "human language" are considered part of the normative definition of that guideline.
Now, having said that, should you still ensure the symbol or glyph can be resized and readable? Absolutely. Is it required by WCAG? No.