Manual:$wgThumbnailNamespaces

Thumbnail settings: $wgThumbnailNamespaces
Defines what namespaces thumbnails will be displayed for in Special:Search.
Introduced in version:1.40.0 (Gerrit change 828553; git #c4a36b00)
Removed in version:Still in use
Allowed values:(array)
Default value:[ 6 ]

Details

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Defines what namespaces thumbnails will be displayed for in Special:Search. This is the list of namespaces for which thumbnails (or a placeholder in the absence of a thumbnail) will be shown.