Hyphens, En Dashes, Em Dashes

Q. Hi CMOS—I work in mortgages, and with the increasing popularity of a “digital lending process” come electronic signatures. No one in my company can seem to agree on how to style this particular term, and as you can imagine, it comes up quite a lot. I’ve seen it four ways:

e-sign(ature)
E-sign(ature)
e-Sign(ature)
eSign(ature)

As I’m working on our in-house style guide, I’m also having to decide how it’s styled in a title or section heading of a policy document. Currently, I have eSignature as a noun and e-sign as a verb, and when it’s a verb capitalized in a title or section heading, it’s E-sign. I need to decide on four styles: (1) noun in a sentence, (2) noun in a title or at the beginning of a sentence, (3) verb in a sentence, and (4) verb in a title or at the beginning of a sentence. This is making my eyes cross. Am I good with what I have, or do you have a suggestion? I’ve consulted M-W and turned up nothing.

A. CMOS covers this at 7.89 (“Hyphenation Guide”), in section 3 under e: “Hyphenated except for email (a departure from previous editions) and certain proper nouns.” Note that capping the S in e-Signature gives it the look of a trademarked or branded product. In a title or section heading you would follow the normal CMOS style for nouns or verbs beginning with a hyphenated prefix: E-signature, E-sign. Please see CMOS 8.161.