In addition to the basic hashtags (#votereport, #machine, #registration, #wait:n, and #EPXX) these are a handful of additional tags for advanced users:

#challenges -- there are widespread challenges occurring at the location.

#hava -- accessibility issues (vision, etc.).  [HAVA is the acronym is for Help Americans Vote Act]

#ballots -- out (or running out) of paper ballots

#good/#bad -- the overall experience