groff: Tab Stops

 
 5.1.4 Tab Stops
 ---------------
 
 'gtroff' translates "tabulator characters", also called "tabs" (normally
 code point ASCII '0x09' or EBCDIC '0x05'), in the input into movements
 to the next tabulator stop.  These tab stops are initially located every
 half inch across the page.  Using this, simple tables can be made
 easily.  However, it can often be deceptive as the appearance (and
 width) of the text on a terminal and the results from 'gtroff' can vary
 greatly.
 
    Also, a possible sticking point is that lines beginning with tab
 characters are still filled, again producing unexpected results.  For
 example, the following input
 
            1          2          3
                       4          5
 
 produces
 
            1          2          3                     4          5
 
    SeeTabs and Fields.