How to use [vocabulary]

The reference page of vocabulary has its arguments, constraints and declaration.

Returns the name of every static slot in your system, optionally passing in a string, or an expression leading to a string, which is a filtering condition, where the slot must start with the filter specified to be considered a part of the end result.

// Returns ALL slots in your system.
vocabulary

// Returns only slots starting with [io.file]
vocabulary:io.file

Notice, inside a [whitelist] invocation this slot only returns the slots the whitelist allows, so it tells the code running inside what it can actually invoke. A whitelisted slot that is pinned to an argument is returned once by name, regardless of how many different arguments it is pinned to.