SIGMAS is theoretically governed by its constitution and bylaws, which are available in .pdf format here, most recently updated on September 21, 2018. It is accompanied by an inaugural poem composed by the first Secretary/Poet Laureate, Chris Duffy. Contact the current Secretary for details about Constitution and Bylaws updates.
A list of SIGMAS policies is available to any SIGMAS member upon request; contact the SIGMAS Secretary for a current document.
The most recent general meeting took place on Sept 18, 2020. The minutes of that meeting can be found here, and are not copy and pasted below, because if the effort is put in to LaTeX it, it may as well be viewed that way. No pity is directed towards users of computers without pdf readers. The executive offers its apologies, and hopes such users move into the 21st century soon.

List of Minutes (.pdf format):