.VSDM File Extension

Visio macros are used to automate repetitive drawing tasks such as setting shape sizes and positions or setting page formatting options. They may be written from scratch with VBA source code or recorded as a series of user actions (Tools → Macros → Record New Macro).

NOTE: The VSDM format, as well as the VSDX format, were introduced with Visio 2013. Previous versions of the software used .VSD and .VDX files for drawings.