Context Navigation

Changes between Version 3 and Version 4 of Ticket #17447, comment 27

v3	v4
7	7	1. It applies the filter ''before'' calling `wp_parse_args`, which prevents removing required arguments via the filter (as any missing keys will simply be added via `$defaults`).
8	8	2. The post type name is sanitized earlier on and passed to the filter as the second argument.
9		3. The filter is only applied to non-built-in post types (i.e. custom post types, post types with an `_builtin` false).
	9	3. The filter is only applied to non-built-in post types (i.e. custom post types, post types with `_builtin` false).
10	10
11	11	As far as post type labels are concerned: these are already filterable in `register_post_type`, as it calls `get_post_type_labels` which has been filterable (`post_type_labels_{$post_type}`) since 3.5.