Kenneth G. Wilson (1923). The Columbia Guide to Standard American English. 1993.
ilk (n.)
long ago meant like or same and was used in Scotland to identify people by associating them with the place they hailed from, as in McLeod of that ilk, meaning McLeod of the same (place), or McLeod of McLeod. But today the only Standard meaning of ilk in English is kind or sort: We dont socialize with people of that ilk.