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Usage: {{sigbox}} to put {{User:USER/sig}} in a box. But with the user's name instead of "USER". One variable can be used to specify the user's name. Otherwise, not using a variable will simply display the signature of the user space it's applied on (i.e. a user talk page). If the user has a '/Sig' sub-page instead of '/sig' use the second variable. (i.e: {{sigbox||0}}, {{sigbox|username|0}})

To put text other than a template-sized sig inside the box, use {{sigbox-raw}}.