One is to change your default profile options to automatically uncheck "Disable HTML in this message" (assuming the admin hasn't limited that). Then just use a <div style="margin: auto;"> or the older <center> tag in your signature.
Another way to do this is to add a Center bb code tag to the jForum bb_config.xml file. E.g.
This will allow
BB tags to be used in both posts and signatures. [originally posted on jforum.net by monroe]
Some minor corrections... I said to UNCHECK the disable html option... i.e.. ENABLE html. Having this enabled will also include what is in the signature. If you do it in your profile settings, it will automatically enable html for all your postings... unless the admin has forced this off.
You should be able to include the HTML to center your sig without needing to bug the admin.
FYI - There is no CENTER or ALIGN BBCode by default. The tag above would have to be added by your admin. [originally posted on jforum.net by monroe]