A note is one piece of content created and posted under the character. When a note is created, the user could set a content URI for that note, and also set the link module and mint module for the note. So when that note is linked or minted in the future, the corresponding module can be triggered.

Similar to character metadata, the content of one note is set by a URI that points to the content metadata. That URI can be ipfs protocol or https protocol or whatever else, which could be freely chosen by applications or users. Crossbell just proposes a suggested note metadata specification.

Besides, when a note is posted, the user could decide whether the content URI, link module, and mint module can be modified using a locked flag. With the locked set as false, that content URI, link module, and mint module can be modified at any time. Otherwise, they cannot be modified anymore.

That flag is an indicator for others interested in minting this note. Typically a note with locked set as true and with content in non-editable storage, e.g. content URI in ipfs protocol, could be more persuasive and fair for those who want to mint.

There’s the delete option for a note. But we all know the essentiality of a decentralized world is that nothing can be deleted completely, as long as there’s a node willing to hold that copy. So, the delete operation on Crossbell is just an indicative flag to provide more convenience for both content creators and content consumers. Deleted notes cannot be linked or minted anymore. But the content URI will not be emptied.