= Index Category Key
:description: Reference list of the available index category keys and their value types.
:navtitle: Index
:source-language: yaml

The keys in the `index` category control the spacing and number of columns in the autogenerated index section.

[cols="4,4,6a"]
|===
|Key |Value Type |Example

|column-gap
|xref:measurement-units.adoc[Measurement] +
(default: `$base-font-size`)
|[source]
index:
  column-gap: 12

|columns
|Integer +
(default: `2`)
|[source]
index:
  columns: 2
|===