Do you have a reference for this particular usage of slash? In print, “x / y” is often used to mean “item x out of y” [0], for example in page numbers. I’m only familiar with using slashes for ranges in ISO 8601, where it has purely syntactic reasons and (AFAICT) doesn’t adopt any preexisting convention.
I imagine the slash in CSS grid is for similar syntactic reasons, because the syntax also admits hyphenated identifiers [1] (custom-ident), which precludes the use of “-”. (They could have used a range operator like “~” or “..” though.)
I imagine the slash in CSS grid is for similar syntactic reasons, because the syntax also admits hyphenated identifiers [1] (custom-ident), which precludes the use of “-”. (They could have used a range operator like “~” or “..” though.)
[0] https://en.wikipedia.org/wiki/Slash_(punctuation)#Numbering
[1] https://developer.mozilla.org/en-US/docs/Web/CSS/grid-column...