XS_DIMENSION_DIGIT_GROUPING_CHARACTER
Category in Advanced options dialog: Dimensioning - general
Use this advanced option to specify which separator character to use in large dimension values. For example, entering a comma (,) results in 154321 becoming 154,321. If you do not specify a character, Tekla Structures uses a space in dimensions when you set Digit grouping to Yes in Dimension properties (Use grouping in GA drawings). By default, no value is set.
This advanced option is model specific and the setting is saved in the options database. Reopen the model to activate the new value.