Context Sentence: The difference between standard and non-standard, it should be noted, has nothing in principle to do with differences between formal and colloquial language.

Source: Peter Trudgill Sociolinguistics: An Introduction to language and Society, Dialect On Standar English Accent/ R.P.

Definition: adj. of words, phrase, etc belonging to or suitable for normal conversation but not formal speech or writing (Oxford Advanced Learner's English--Chinese Dictionary, Fourth Edition, 1998)

Memonic:'colloquy' means talking or conversation, colloquial can be easy to remember.