Question on Ethereum ERC standard ERC1400

According to definition of ERC1400 here https://github.com/ethereum/eips/issues/1411

it has the ERC-1643: Document Management Standard.

now my question is, How do these documents/files stored? are they stored in the contract as a hash? are they uploaded somewhere, if so, where?

Also, while were at it, were can I find sample codes/resources for various ERC standards as well, I dont seem to find any sample codes on theses ERC standards everywhere :(

Solution

Note that both standard proposals (ERC-1400 and ERC-1643) are currently (April 2021) still in the draft phase (for over 2 years since they were created). Meaning they haven't been approved by the core team, and not many developers are going to follow an unapproved standard (or publish code samples).

How do these documents/files stored?

The draft of ERC-1643 only defines an interface (function names, argument datatypes, ...), not the actual implementation (how to store the data - that's up to each developer to implement to their use case).

The string _uri that the standard defines as one of the arguments, can be:

IPFS (decentralized storage, my guess is that this is going to be the most common use case)
off-chain file sharing service such as Google Drive
or it can even be an URL accessible only on some private networks
basically any valid URI (so even ftp://, skype:// or tel:// link)