For example, Wikibase special pages include:
"Create a new Lexeme"
"Create a new item"
"Create a new property".

This should be made consistent, choosing a single capitalization scheme. Other lexeme data types like "Form", and "Sense" are often capitalized in the extension's interface, maybe to highlight that ordinary words are being used in a jargon-y sense? Is this intentional? If so, should we consider also capitalizing Wikibase types like "item"?