Where is the best place to put transcriptions?

If I’ve scanned a page of handwritten notes, I may want some of the text to be searchable. But since I cannot recognize the text with with Optical Character Recognition (OCR) function, I need to transcribe any part of the text I want to be able to search. But, I wonder where to write it?

Should I write it as a separate annotation file? Transcribed text plays a different role from my usual annotations; it’s not my notes on a file, but rather the contents of the file itself.

I could write it into the Annotations field in the Annotations & Reminders Inspector. But is that the best place?

There’s actually no preference or best place. Typical options are annotations, Finder comments or custom metadata text. Another possibility is to use a stand-alone document (e.g. plain/rich text, Markdown, formatted note) linking to the scan.

For me, if the transcription is a separate document
I would then merge the two documents

As @cgrunenberg, there is more than one option available. However, the annotation file method is used by many people for taking notes off to the side.