A style rule is a qualified rule that associates a selector list with a list of property declarations and possibly a list of nested rules. They are also called rule sets in CSS2.
As the above quote from W3C indicates, it seems like the W3C considers “rule set” to be a bit of an outdated term, preferring the term “style rule” (or possibly “rule” for short).
I never noticed that! “Rule set” is so gosh darned branded on my brain that it’s gonan take losing a lot of muscle memory to start using “style rule” instead. I didn’t see a specific note in the spec’s Changes section, but you can see the change in the table of contents between versions:
Louis nicely sums up the parts of a style rule as well:
/* Everything below is a style rule (or rule set, or just rule) */
section { /* Everything between the braces is a declaration block */
margin: 0 20px; /* This line is an individual declaration */
color: #888; /* Another declaration */
}I know nothing of the context and, at first, I was gonna poo-poo the change, but “style rule” really makes sense the more I sit with it. If the property:value pairs are declarations that sit in a declaration block, then we’ve got something less like a set of rules and more like one rule that defines the styles for a selector with a block of style declarations. 👌
Once again, naming things is hard.
