I think I slightly prefer the "No Major Skips" name to "Glitchless," because I think it more accurately reflects what the actual rules cover:

-The major skip in 4-1 is disallowed, even though I don't think it can reasonably be called a "glitch." Same with the clock trick in 5-1. Both of these are major skips that clearly violate the spirit of the category (and the actual rules, of course), but the title "glitchless" doesn't really give any hint that they're not allowed.

-Other small tricks, like shooting through giant moos, plane jumps, skipping Gelg Bolm's pollen (??) attack, and things that let you regain control of Klonoa earlier than intended (shooting after taking damage, using the double jump storage to open doors faster), and general hitbox weirdness ARE allowed, even though I can imagine a casual viewer seeing them and complaining that they look like glitches and are therefore obviously cheating.

-The first line of the rules already literally says "Should be understood as 'no major skips.'"

That said, I don't really care what the title is, but I DO like the rules as they currently are and don't see any harm in changing the name to something that is more in line with what the category actually is.

EDIT: Balneor pretty much already said everything I just said in his previous post.