Appropriate title case: 'em or 'Em or 'EM

It's a common practice to capitalize headings/titles of articles. But is there a correct or conventional way to capitalize words in titles that are apocopated apheresed at the beginning?

E.g.

Disable Feeds (Make 'em Inaccessible) On Your Site

Yes, I do understand that using Them instead of 'em would be more proper, but I really wanted to know about this anyway.

The Chicago Manual of Style's convention on headline-style capitalization does not mention words beginning with apostrophes (8.157–159). It gives seven rules. The first rule is to capitalize the first and last word of titles and subtitles (e.g., 'Twas the Night Before Christmas), and the other six concern part of speech. This would seem to indicate whether to capitalize a word beginning with an apostrophe should depend on its placement within the title and part of speech, and would in your case give you "Make 'Em Inaccessible," which to me looks terribly awkward.

However, before laying out its seven rules, the Manual says

The conventions of headline style are governed mainly by emphasis and grammar.

This hints at what it later says explicitly; the rules are arbitrary.

In a previous edition (the 15th, 8.167), it says

If you are not sure what grammatical function a word is performing (or even if you are), try reading the title aloud: if you would stress the word, capitalize it; if not, lowercase it.

This would seem to indicate "Make 'em Inaccessible." Up to you whether you want to go with the more rigid current recommendations or the more subjective guideline the Manual prescribed ages ago (in 2003).

The accepted practice appears to be to carve out an exception to the normal rules of titling. Consider the play Give ’em Hell, Harry!, whose title has an ’em in it — in that literal capitalization.