Crate Name Uniqueness

For a given registry server, a "crate" is identifiable by its name, which is unique to the crate registry. Each organization is its own registry server in this sense; if organization A publishes crate "abc", it will not prevent organization B from also publishing a crate that is named "abc".

Permitted Crate Names enforces the same rules as regarding valid crate names:

Cargo itself allows names with any alphanumeric, -, or _ characters. imposes its own limitations, including the following:

  • Only allows ASCII characters.
  • Only alphanumeric, -, and _ characters.
  • First character must be alphabetic.
  • Case-insensitive collision detection.
  • Prevent differences of - vs _.
  • Under a specific length (max 64).
  • Rejects reserved names, such as Windows special filenames like "nul".