pre_user_email
Filter Hook: Filters a user’s email before the user is created or updated.
Source: wp-includes/user.php:2211
pre_user_nickname
Filter Hook: Filters a user’s nickname before the user is created or updated.
Source: wp-includes/user.php:2262
pre_user_first_name
Filter Hook: Filters a user’s first name before the user is created or updated.
Source: wp-includes/user.php:2273
pre_user_last_name
Filter Hook: Filters a user’s last name before the user is created or updated.
Source: wp-includes/user.php:2284
pre_user_display_name
Filter Hook: Filters a user’s display name before the user is created or updated.
Source: wp-includes/user.php:2314
pre_category_nicename
Filter Hook: Filters the category nicename before it is sanitized.
Source: wp-includes/taxonomy.php:1837
pre_user_login
Filter Hook: Filters a username after it has been sanitized.
Source: wp-includes/user.php:2134