noun which may take the genitive case particle 'no'
unregistered; non-registered
Describes something not yet entered into an official list, database, or registry. Often used in administrative, legal, or technical contexts.
未登録のユーザーはこの機能を使えません。
Unregistered users cannot use this feature.
その車両はまだ未登録です。
That vehicle is still unregistered.
未記入 means 'not filled in' (e.g., a blank form), while 未登録 specifically refers to lack of registration in a system.
Compound of 未 (mi, 'not yet') + 登録 (tōroku, 'registration').