To understand this, you should be familiar with CivitAI metadata.

Models, versions, files, images, and creators may have additional entries.

If you want to retrieve JSON as close to the original as possible, look
for keys beginning with "yansefy_" in those places and remove them. You
may not want to do this, though.

This is a list of all possible entries:
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model['yansefy_deleted'] :
version['yansefy_deleted'] :
file['yansefy_deleted'] : 
image['yansefy_deleted'] :

Optional, false by default. Self-explanatory.
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creator['yansefy_aka'] :

Optional, an array of all known aliases for a creator. Only present if 
creator['username'] isn't the only one.
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model['yansefy_source'] :
version['yansefy_source'] :
file['yansefy_source'] : 

Optional, "CivitAI API" by default.

A string indicating the source from which I'm getting the metadata. It can
now have one of these values:

"CivitAI API"
"HuggingFace Crawler"
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version['yansefy_order'] :
file['yansefy_order'] : 
image['yansefy_order'] :

We're working with deleted items, so the "index" key is sometimes outdated
and unhelpful. To determine the order in which items are displayed, I use
"yansefy_order." The lowest values ​​should be displayed first.
----------------------------------------------------------------------------
model['yansefy_id'] :
version['yansefy_id'] :
file['yansefy_id'] : 
image['yansefy_id'] :
creator['yansefy_id'] :


This is the ID of the model/version/file/image/creator in my personal
database.
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version['yansefy_parent_id'] :
file['yansefy_parent_id'] : 
image['yansefy_parent_id'] :

This is the ID of the parent item in my personal database. The parent item
is a model ID for versions and a version ID for files and images.
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file['yansefy_hashes'] : 

Optional.

This is a pool of known hashes for this file. If not present, no
alternative hashes are known.

Format:

file['yansefy_hashes'][SOURCE][HASH1, HASH2, HASH3...]

SOURCE can be:

"CivitAI API" : The hash was seen in metadata from the CivitAI API
"HuggingFace Crawler" : The hash was seen in metadata from HuggingFace
                        repositories.
"HuggingFace (Old Hashes)" : The hash was seen in metadata from HuggingFace
                        repositories, and they are known to be old.

A file can have multiple hashes from different sources.