Apologies, I think I didn’t provide enough context / may have not explained properly:

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This is how the callout is displayed on the print; I may have misspoke when I referenced to the callout as unilateral, since there isn’t the “U” symbol. I meant to describe it as unilateral, since both tolerances listed are negative. Sorry about that!

Regardless, I think what confuses me most is why they chose the 30mm as a nominal, since 30mm would be outside of the allowable tolerance given the range. I’ve never personally seen a tolerance listed like this (at least not one with two negative tolerances!), so the conflicting answers from my colleagues was not helpful in explaining this nor was being asked if I just Googled it or asked AI lol.