Change the wording of the registration screen, which visitors use to create an account when Anyone can register is ticked in Settings → General → Membership.

Settings
- Message above the form: WordPress says “Register For This Site”.
- Username label: the label above the username field.
- Email label: the label above the email field.
- Confirmation note: the line under the fields that says a confirmation email will be sent.
- Register button: the text on the button.
Leave a field empty to keep WordPress’s wording.
Change the wording
- Type the new text in the fields you want to change.
- Click Save changes, then use Preview → Registration.

The email new users receive
After registering, users get the New User Registration (User) email with a link to set their password. Change its wording under Settings → Emails → User Emails.
See also Login Form Texts and User Emails.
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