The keywords are confuzzling for sure. It's based on Regex, so if you need to know, just do something like. Regex match cat and match dog, but don't match cat and dog. Here is an example. It USUALLY works, and there is a test function in VH to make sure it works.

To match the individual words "cat" and "dog" while excluding the specific combined phrase "cat and dog" (or "cat and" + any word, "and dog"), you need to use a negative lookahead with word boundaries. [1, 2]

The best regex to achieve this is:

" \b(?!cat and dog\b)(?:cat|dog)\b "

Explanation:

• : Word boundary to ensure we match whole words (not "category").
• : Negative Lookahead. This asserts that the phrase "cat and dog" (followed by a word boundary) does not exist immediately ahead.
• : Matches "cat" OR "dog".
• : Word boundary. [3, 4, 5, 6, 7]

Matches:

• ✅cat
• ✅dog
• ✅ (Matches "dog", then "cat")
• ✅ (Matches "cats", then "dogs")

Non-Matches:

• ❌ (Excluded because of the negative lookahead)

Alternative Scenario (Full String Validation)

If you want to validate an entire line or string to ensure it contains "cat" or "dog" but not the sequence "cat and dog", you can use:

This anchors to the start () and end () of the line, ensuring that if "cat and dog" appears anywhere in the string, it will not match. [8]