but perhaps only 5% or so would ever describe subtraction as non-communicative

Then one can only wonder what they make of the idea of left- or right-associativity in Operator Precedence and Associativity. (UPDATE: On re-reading, the substitution of ‘communicative’ for ‘commutative’ is quite funny.)

technical or scientific language used to convey a false impression of meaningful technical or scientific content

Or perhaps “unusual-to-domain language used to convey an impression of humour”, a special case of ‘joke’. (If ‘vulgar’ were some technical CS term, then your objection might be appropriate, but I think that's not the case.)

Anyway, much of this thread has been occupied with patches to documentation, and your where/when catch was a good one (it bugged me, too). If you find the language that offensive, and you've got better, then why not submit a patch?