5.1.6 Tabs and Leaders

GNU troff translates input horizontal tab characters (“tabs”) and Control+A characters (“leaders”) into movements to the next tab stop. Tabs simply move to the next tab stop; leaders place enough periods to fill the space. Tab stops are by default located every half inch measured from the drawing position corresponding to the beginning of the input line; see Page Geometry. Tabs and leaders do not cause breaks and therefore do not interrupt filling. Below, we use arrows → and bullets • to indicate input tabs and leaders, respectively.

1
→ 2 → 3 • 4
→ • 5
⇒ 1         2       3.......4         ........5

Tabs and leaders lend themselves to table construction.²⁴ The tab and leader glyphs can be configured, and further facilities for sophisticated table composition are available; see Tabs and Fields. There are many details to track when using such low-level features, so most users turn to the tbl(1) preprocessor to lay out tables.