Sometimes the issuers make explicit statements about whether a coin is intended for circulation or not, and the statements occasionally seem illogical.
Catalog editors (both for printed catalogs and Numista editors) make decisions based on metal content (compared to other coins of the era), mintage quantity, and how the coins are distributed. These are often inconsistent.
And sometimes Numista editors click the wrong entry or make a quick decision without a good evaluation of the situation.