As a writer, I keep track of a fair bit of data: Magazine deadlines, the pieces I have out where, the drafts I'm working on, acceptances, and then some. I don't use Excel because it's a pain... just a document with a search feature. It works well enough, but the document that holds my acceptances really needs an exclusivity note.
People who don't write (but want to) often have this image in their heads of crafting an amazing story in a night, getting accepted within a week, and blasting social media with their awesomeness as soon as it hits print. Writers know the wait after we send off our work is the DMV on a garbage barge and not McDonald's on a jet ski (not even considering how long a great story takes to write/polish). If we get that rare acceptance, and the magazine is in print, an editor may request that we not to share our work for a certain period.
The only acceptance I've received this year asked me for a year's exclusivity after the issue is published in June. These periods vary greatly among magazines. Some want you to wait until their next issue comes out, two years in the future, or not at all. And I don't keep track. It's utterly foolish, especially if I sign a contract stating I agree to wait.
I might be in breach of contract someday due to my carelessness, though I doubt anyone would take me to court over a matter worth five dollars. But they could (and probably would) blacklist me and/or tell other editors I'm dishonest. I didn't spend decades in obscurity just to be known as "that untrustworthy writer".