For notating fretted stringed instruments you can use tablature (or tab for short). Stave'n'Tabs, as its name implies, supports that type of musical notation and provides you with convenient tools to modify tablatures.

To edit tablature first select the TablatureInput type - Tablature input type in the toolbar or press Command T . So the cursor starts indicating the current string for which you can enter fret numbers with digit keys on the computer keyboard. Navigation is done using mouse or Arrow Up Arrow Down Arrow Left Arrow Right keys.

Editing tablature
Editing tablature with 2nd string selected

Virtual fretboard in the Virtual Instruments board is another useful option for editing tabs. It can show labels for notes at their positions on the fretboard respectively to current tuning.

Virtual fretboard with note labels
Virtual fretboard with note labels