# Radio Button Group > [HTML Version](radio_button_group.htm) **Group=###** Associates radio button cells within the current column with a specific radio button group, so as to allow more than one group of radio buttons in a row, or even a set of related cells in the same column to form a group. ### is the group number, 0-252. Columns without a Group= clause are assigned group 0. Groups 253-255 are reserved for vertical groups: | **Group** | **Description** | |------|------| | 255 | Entire column is a single group | | 254 | XTF\_MLVL: Items with same immediate parent form a group | | 253 | XFF\_MLVL: Items at same level form a group | If the tree is not multi=level, all three of the above act like 255, i.e. only one radio button in the entire column can be selected at a time. Note that as with horizontal groups, enforcement of the only-one-selected-per-group rule occurs only when you change a radio button during editing. It is up to the application to enforce the rules during loading and display operations.