On Reddit it is (or at least was) considered polite if you edit your posts to correct spelling errors or clarify something that you added ‘EDIT: whatever I did’ to the bottom of your post. Is that the done thing here? Should it be?
I only followed that etiquette if it’s necessary information, otherwise future readers are going to have their time wasted.
Additionally, if the comment is sensitive in nature you could justify an Edit: remark.
But otherwise I just edit and leave it at that.
I’m seeing people doing Edit:, but not for typos. Seems unnecessary.
One tip that helps cross-instance communities connect: format your link as [ text ] ( /c/community@instance.whatever ) without the spaces. It keeps you on your local instance when browsing to another instance’s community.
Whether on Reddit or a pre-Reddit forum, I usually never bothered to add an ‘ETA:’ footer for small spelling or grammar changes, or for larger changes edited in immediately after posting (as an author I don’t exactly have the most ordered thought process…). Anytime I added information more than a few minutes after posting – for example, providing citation links or adding nuance to something that didn’t come across as clearly as I intended – I would usually provide a footer summarizing those changes for posterity. Unfortunately, reddit being reddit the discussion would usually have moved far past my post at that point.
I usually leave an "edit: " footer if the edit was significant. I just fixed a typo or spelling then I do it silently.
I don’t think that has really been common practice for many years. Fake “Edit” messages for comedic affect have long outnumbered real edit messages.