This does not indicate that the active theme supports the feature, it only describes the feature's supported options.
No Hooks.
Returns
true|WP_Error. True if the theme feature was successfully registered, a WP_Error object if not.
Usage
register_theme_feature( $feature, $args );
$feature(string) (required)
The name uniquely identifying the feature. See add_theme_support() for the list of possible values.
$args(array)
Data used to describe the theme.
Default: array()
type(string)
The type of data associated with this feature. Valid values are 'string', 'boolean', 'integer', 'number', 'array', and 'object'. Default: 'boolean'
variadic(true|false)
Does this feature utilize the variadic support of add_theme_support(), or are all arguments specified as the second parameter. Must be used with the "array" type.
description(string)
A short description of the feature. Included in the Themes REST API schema. Intended for developers.
show_in_rest(true|false|array)
Whether this feature should be included in the Themes REST API endpoint. When registering an 'array' or 'object' type, this argument must be an array with the 'schema' key. Default: not being included
schema(array)
Specifies the JSON Schema definition describing the feature. If any objects in the schema do not include the 'additionalProperties' keyword, it is set to false.
name(string)
An alternate name to be used as the property name in the REST API.
prepare_callback(callable)
A function used to format the theme support in the REST API. Receives the raw theme support value.