When used in forum posts to indicate a change, what does 'ETA' mean?

“When used in forum posts to indicate a change, what does ‘ETA’ mean?” — “Edited to add.” In this context, ETA tells readers that the author returned to an existing post and inserted new information after the original submission.

Forum users often place ETA before a sentence or paragraph added later, especially when they want to clarify a detail, answer a follow-up question, or acknowledge information that appeared after posting. It makes the timeline of the message more transparent without requiring a completely new reply.

This meaning is separate from the much older and still common “estimated time of arrival.” The surrounding context determines which expansion is intended: a travel update uses the arrival meaning, while a message-board edit uses “edited to add.”

“Edit to add” is understandable, but “edited to add” is the conventional expansion because it describes what happened to the already-published post. ETA can also appear in variants such as “ETA: corrected a typo” or “ETA: adding more context.”