What is the correct format for using commas after periods? [duplicate]

Solution 1:

I agree a comma immediately following a period or full stop does look weird, but it would look worse without!

"Bob, C.J, Greg and Charles all went to the store."

So your way of punctuating was in the end, correct.

Bob, C.J., Greg and Charles all went to the store.

The rule is that a comma mustn't go after an initial, ever.

I did a bit of research to double check and I didn't find anything that contradicted my gut feeling.

http://www.noslangues-ourlanguages.gc.ca/bien-well/fra-eng/ponctuation-punctuation/etc-eng.html

http://wiki.answers.com/Q/Should_there_be_a_comma_after_the_abbreviation_Inc

However, you could change the order of names thereby avoiding the inaesthetic coupling of the period and comma.

"Bob, Greg, Charles and C.J. all went to the store."

EDIT: I thought it best to rephrase and change the original modal verb, "shouldn't" to "mustn't" to avoid any possible misinterpretation. I hope, I've made myself clearer!

Solution 2:

The periods in C.J. don't punctuate. They act more like letters, and can thus be considered spelling rather than punctuation. Spelling doesn't affect how you use commas, so feel free to use a comma after C.J. whenever it makes sense to do so.

The only exception I can think of is when you end a sentence with a word that ends with a period. In that case, the period has to do double duty: it's both spelling and punctuation. Adding a second period would go against convention.