I have seen several business with large signs proclaiming ‘COMMING SOON’.
Two of the major spelling rules of English are the ‘drop the e’ rule and the ‘double the consonant’ rule, but those two rules can never apply at the same time: the ‘drop the e’ rule only applies when there is a ‘magic e’ at the end of the word, and ‘double the consonant’ rule only applies when there is a consonant at the end of the word.*
The reason why the signwriters have fallen into this this trap is that come is one of the very few verbs with a ‘magic e’ which has a short consonant earlier in the syllable. Dropping the ‘e’ results in a semi-word which has a short vowel and a final consonant, which is enough to trigger the second rule. (The only other verbs I could reasonably find are have, give, live, love** and I suspect that very few people seriously write havving, givving, livving or lovving.***)
I would never write comming, but I know that there are several instances of becomming in the diary I kept during my first stay in Korea (2006-09), so no-one’s perfect. (The spell checker of my word processing program of the time did not underline misspellings on the screen.)
*Both rules are more complex than that, but that’ll do for the purposes of this post.
**There are more multi-syllabic verbs, including but not limited to manage, determine, encourage, notice and examine, in which the previous vowel is unstressed and reduced.
***There are many instances of each on the internet, mostly either in jest or clearly by mistake, but some apparently serious, albeit informal. I couldn’t find a serious, formal instance of any. (I am prepared to ignore http://www.livving.com as a company/product name.)