What does the '【25†source】' marker mean in OpenAI's Assistant API responses?

Below is an explanation in markdown format:

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Explanation of the "【25†source】" Marker

The string 【25†source】 is an inline reference marker automatically added by the retrieval tool. Here are the key points:

• Internal Reference:
  The number (e.g. 25) is an internal identifier. It doesn’t indicate a page number or any visible section number of your uploaded document. Instead, it may represent a position or a unique ID from how the document was split into chunks when indexed.

• Artifact of the Retrieval Process:
  Since the retrieval tool processes and splits the source document into chunks for more efficient search and retrieval, these markers serve as hints to the system (or developers) for tracking the origin of the text snippet. They are not meant for direct interpretation by end users.

• Interpretation:
  For most applications, you can essentially ignore the marker. It does not imply any additional context (such as a citation or footnote) that you need to present to your users. Its purpose is mostly internal—to help the system identify which part/chunk of the document was used.

• Action for Developers:
  If you need to display retrieved text without these technical details, you might consider post-processing the text to remove or replace these reference markers before presenting them.

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This explanation should help you understand that 【25†source】 is not an error but an artifact of how the API’s retrieval tool processes and records source information.