:Category:Article namespace categories
{{Maintenance category|container=true|desc=Contains categories whose members should only be in the main namespace.}}
[https://petscan.wmflabs.org/?outlinks_yes=&language=en&ns%5B8%5D=1&ns%5B15%5D=1&ns%5B118%5D=1&ns%5B10%5D=1&ns%5B13%5D=1&ns%5B2301%5D=1&ns%5B711%5D=1&ns%5B5%5D=1&ns%5B108%5D=1&edits%5Bbots%5D=both&ns%5B101%5D=1&cb_labels_yes_l=1&cb_labels_any_l=1&ns%5B9%5D=1&interface_language=en&categories=Article_namespace_categories&ns%5B100%5D=1&ns%5B2303%5D=1&ns%5B829%5D=1&ns%5B1%5D=1&ns%5B3%5D=1&ns%5B11%5D=1&ns%5B6%5D=1&ns%5B2302%5D=1&edits%5Banons%5D=both&search_max_results=500&ns%5B828%5D=1&depth=19&ns%5B12%5D=1&active_tab=tab_pageprops&ns%5B7%5D=1&ns%5B109%5D=1&ns%5B4%5D=1&ns%5B446%5D=1&ns%5B447%5D=1&ns%5B710%5D=1&cb_labels_no_l=1&ns%5B2%5D=1&ns%5B2300%5D=1&ns%5B119%5D=1&edits%5Bflagged%5D=both&project=wikipedia This Petscan query] can be used to detect any pages in other namespaces.