Subscribe to The Chicago Manual of Style Online
Q. We want to know the usage of “etc.” at the END of a sentence, that is, as the last word of a sentence. Is it spelled out?
A. The expression “et cetera” is rarely used. Its abbreviation “etc.” is discouraged in formal writing; CMOS recommends that, if used, it should be confined to parenthetical material or lists and tables. There is, however, no difference between the abbreviation and the two-word Latin expression it represents, and the position in a sentence has no bearing on which is more appropriate. For the use of commas with “etc.” and some of its English equivalents, see CMOS 6.20.