Manual:$wgUploadDialog

The $wgUploadDialog global allows for configuration of the upload dialog (selecting fields to display, modifying the licensing options, and choosing special formatting for the file page which will be created and the upload comment).

This applies also to foreign uploads to this wiki, if configured (the configuration is loaded by remote wikis using the action=query&meta=siteinfo API).

Default value
See below for documentation of each property. None of the properties may be omitted.

fields
Fields to make available in the dialog. means that this field is visible,  means that it is hidden. Note that you also have to add the matching replacement to the 'filepage' format key to make use of these.

Available fields: The "Name" field can't be hidden.
 * 'description' - file description
 * 'categories' - categories
 * 'date' - file creation date

licensemessages
Suffix of localisation messages used to describe the license under which the uploaded file will be released. The same value may be set for both 'local' and 'foreign' uploads.

The 'local' messages are used for local uploads on the wiki. The 'foreign' messages are used for cross-wiki uploads from other wikis to the wiki, if configured.

The default values correspond to:
 * upload-form-label-own-work-message-generic-local:
 * upload-form-label-not-own-work-message-generic-local:
 * upload-form-label-not-own-work-local-generic-local:
 * upload-form-label-own-work-message-generic-foreign:
 * upload-form-label-not-own-work-message-generic-foreign:
 * upload-form-label-not-own-work-local-generic-foreign:
 * upload-form-label-not-own-work-message-generic-foreign:
 * upload-form-label-not-own-work-local-generic-foreign:

comment
Upload comment to use. Available replacements: This allows the wiki and the page where the upload was initiated to be documented in the upload comment.
 * - domain name from which a cross-wiki upload originates
 * - wiki page name from which an upload originates

Starting with MediaWiki 1.28, this can also be set to an array to specify different upload comments for local and foreign uploads:

format
Format of the file page wikitext to be generated from the fields input by the user. This defines how the specified  are used to construct the file description page.
 * 'filepage' is a wrapper for the whole page. Available replacements:
 * - file description, as input by the user (only if the 'description' field is enabled), wrapped as defined below in the 'description' key
 * - file creation date, as input by the user (only if the 'date' field is enabled)
 * - currently, this is always the value defined below in the 'ownwork' key. The upload dialog may be extended in the future to allow choosing other sources.
 * - linked user name of the uploader. The upload dialog may be extended in the future to allow choosing other authorship information.
 * - currently, this is always the value defined below in the 'license' key. The upload dialog may be extended in the future to allow choosing other licenses.
 * - file categories wikitext, as input by the user (only if the 'categories'field is enabled), or if no input, as defined below in the 'uncategorized' key
 * 'description' - wrapper for the file description, as input by the user. Available replacements:
 * - source wiki's content language. This is mostly useful for foreign uploads.
 * - input by the user
 * 'ownwork' - used for  in 'filepage'
 * 'license' - used for  in 'filepage'
 * 'uncategorized' - used for  in 'filepage' when the user input no categories