We have the first-appearance tag, with the following tag info:
Which was the first movie/show to use a certain characteristic or technique?
Questions with this tag should be looking for the first time something was used either on screen (a special movie characteristic, plot device, etc.) or during production (e.g. cutting technique, special equipment, effects).
Depending on interpretation, this description more or less limits the kind of first appearances one can ask for. I can't, however, find any meta discussion about this tag or its scope specifically. The questions listed below discuss either incidentally and don't really add anything to this.
Do we have or want to create a scope for this type of question?
Somewhat related meta questions: