Blocking words

At the heart of Blocklist for Forms is a list of disallowed words. When a protected form is submitted, Blocklist for Forms checks the submission against this list and rejects anything that contains a match — before it reaches your inbox.

You can use WordPress’s built-in comment disallowed words list, keep a separate custom list just for Blocklist for Forms, or use both.

Option 1 — Reuse WordPress’s disallowed words

WordPress already includes a Comment Disallowed Words list used for moderating comments. Blocklist for Forms can reuse it, so you only maintain one list.

Go to Settings → Discussion.
Scroll to Comment Disallowed Words.
Enter one word or phrase per line. When a comment — or now a form submission — contains any of these, it is blocked.
Save your changes.

Option 2 — Use a separate custom list

If you’d rather keep form-blocking words separate from comment moderation, Blocklist for Forms lets you maintain its own custom blocked-words list.

Go to Settings → Blocklist for Forms.
Choose the option to use a custom blocked-words list instead of (or in addition to) the comment disallowed words.
Enter one word or phrase per line.
Save your changes.

This list is kept independently of the comment moderation list, so changes here don’t affect how comments are moderated.

Choosing between the two

Use the comment disallowed words list if you want a single list shared across comments and forms.
Use the custom list if you want form protection to be independent of your comment moderation rules.
Enable both if you want form submissions checked against each list.

Tips for a good block list

Start with the specific spammy words and phrases you actually receive.
Prefer distinctive multi-word phrases over short common words to reduce false positives.
Review the list periodically as spam trends change.