Use of hyphenation in "mode" names is inconsistent

[ThinkOpenly]

riscv-isa-manual$ grep -i -E 'machine mode|supervisor mode|hypervisor mode' src/* 2>/dev/null | wc -l
57
riscv-isa-manual$ grep -i -E 'machine-mode|supervisor-mode|hypervisor-mode' * 2>/dev/null | wc -l
55

The same problem exists with "[single character] mode", but is a little more difficult to search, so these could be inaccurate:

riscv-isa-manual$ grep -E 'M mode|S mode|H mode' * 2>/dev/null | wc -l
16
riscv-isa-manual$ grep -E 'M-mode|S-mode|H-mode' * 2>/dev/null | wc -l
512

[kbroch-rivosinc]

I would suggest no hyphen for spelled out version (machine mode) and hyphen for abbreviations (M-mode).

[pdonahue-ventana]

I thought that it had to do with whether it's a noun or a compound adjective. "This behavior happens in M mode." (M is an adjective and mode is a noun) vs. "This is M-mode behavior." (M-mode is a compound adjective and behavior is the noun)

That might be way too subtle for all but the most strident grammar nerds. I think that the ability to search for a consistent term is probably the most important thing here.

[aswaterman]

Let's set aside the hyphenation of the abbreviations for the moment.

We try to consistently hyphenate compound adjectives and and not hyphenate nouns. So, a handful of the changes in #2316 should be made, but many of them should not be. @kbroch-rivosinc can you go through them manually and apply this discipline?

[ThinkOpenly]

We try to consistently hyphenate compound adjectives and and not hyphenate nouns.

Should this be added to the "Authoring and Editing RISC-V Specifications"? (If it's already in there, I couldn't find it. There are only a couple of unrelated mentions of "hyphen".)

[aswaterman]

Probably. It is a standard grammatical rule, but one that’s misunderstood enough that it might benefit from explicit mention. Can you take care of that?