Issue #237 - UI for Merge ("mark duplicate") event feature for sysadmin
Issue #238 - UI for Merge ("mark duplicate") venue feature for sysadmin
Issue #237 - UI CSS class
Issue #233 - Class on UI
Issue #239 - UI for Merge ("mark duplicate") area feature for sysadmin
Issue #239 - sanity check
Issue #237 - sanity check
Issue #233 - sanity Check
Issue #238 - sanity check