> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognigy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# User-Defined Slots

*User-Defined Slots* are custom Slots based on your vocabularies or regular expressions, allowing detection of specific phrases, entities, or domain-specific terms.

In Cognigy.AI, you can create the following user-defined Slots:

* [Lexicon Slots](/ai/platform-features/nlu/slots/user-defined/lexicon) — specific words or phrases (and their variations) from a custom word list.
* [Regex Slots](/ai/platform-features/nlu/slots/user-defined/regex) — structured patterns, like phone numbers or emails, using regular expressions.