# UNDOMARKS System Variable [GstarCAD 2026](Help%20System/GSTARCAD/2026/Index.md) → [System Variables](Help%20System/GSTARCAD/2026/System%20Variables/(System%20Variables).md) → [U](Help%20System/GSTARCAD/2026/System%20Variables/U/(U).md) ## Function Description: The UNDOMARKS system variable is used to display the mark number placed in UNDO control stream. (Read-Only) | | | | --- | --- | | Type | Integer | | Saved in | Not saved | | Initial value | 0 | If one group is currently active, the Mark and Back options are disabled. --- [Original help](https://www.gstarcad.net/help/GstarCAD_2026_en-US/detail/systemVariables_Ugsv/UNDOMARKS.html) · © Gstarsoft Co., Ltd.