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Tab stops
HT (Horizontal Tab) advances the cursor to the next tab stop. Default tab stops are set every 8 columns. The tab character (0x09) does not produce visible output — it moves the cursor forward. Tab stops can be set with HTS and cleared with TBC.
Tabs are cursor motion, not spacing characters painted into the grid. The default eight-column stops are a convention inherited from mechanical devices and codified in terminal behavior. Custom stops are rarely used by modern TUIs, but correct HT behavior is still visible in shells, logs, Makefile output, and legacy full-screen programs.
How this is testedautomated
Write tab then "X", verify X appears at column 8 (after the default 8-column tab stop).
Write tab then "X", verify X appears at column 8 (after the default 8-column tab stop).
The same probe runs against headless backends (via Termless) and real terminal apps (via a daemon launched in each terminal). This lets us distinguish parser correctness from rendering correctness.
Analysis2026-05-17
Supported by all 12 tested terminals — universal adoption. Part of the Core TUI baseline.
Supported by 13 of 14 backends (93%)
Terminal Applications
| Terminal | Version | Support | Notes |
|---|---|---|---|
| iTerm2 | 3.6.9 | ✓ yes | |
| Ghostty | 1.3.1 | ✓ yes | |
| VS Code | ✓ yes | ||
| Warp | ✓ yes | ||
| Kitty | 0.46.2 | ✓ yes | |
| Cursor | ✓ yes | ||
| Terminal.app | ✓ yes |