HTS Horizontal Tabulation Set

Set a tab stop at the cursor's column.

ESC H

ECMA-48: §8.3.62 HTS – Character Tabulation Set, p. 46
DEC STD 070: §5.4.5 Horizontal Tabulation Set, p. 5-69
VT220: §4.8 Tab Stops
VT510: HTS—Horizontal Tab Set

Set a horizontal tab stop at the column the cursor is in. The cursor does not move, and the other tab stops are not affected. The next HT or CHT from left of that column stops there.

HTS is a C1 control. ECMA-48 defines it both as the single byte 88 and as ESC H, and the VT510 manual accepts either. libghostty-vt decodes its input as UTF-8, so it accepts only ESC H: a lone 88 byte is not valid UTF-8 and is printed as U+FFFD, the replacement character, and the code point U+0088 sent as UTF-8 is ignored.

TBC clears tab stops, one or all of them.

Support

Terminal	Version	Support	Notes
VT220	manual, 2nd ed., 1984	Yes	§4.8 Tab Stops
VT510	manual, 1st ed., 1993	Yes	HTS
xterm	patch 412, xterm-411a	Yes
libghostty-vt	0f171f6	Yes	`ESC H` only; U+0088 is ignored
pyte	0.8.2, run as a library	Yes	passes the 3 cases that show it working
xterm.js headless	6.0.0, run as a library	Yes	passes the 3 cases that show it working
alacritty_terminal	0.26.0, run as a library	Yes	passes the 3 cases that show it working
ConEmu	build 230724, its documentation	No	not in ConEmu’s ANSI escape codes
rxvt-unicode	9.31, run in a VM	Yes	passes the 3 cases that show it working
VTE	0.84.1, run as a library	Yes	passes the 3 cases that show it working

Validation

HTS-1: Set a stop

\e[?5W    # reset tab stops: 9 and 17
\e[1;5H
\eH
\e[1;1H
\tX

|____X_______________|

HTS-2: The other stops stay

\e[?5W    # reset tab stops: 9 and 17
\e[1;5H
\eH
\e[1;1H
\t\tX     # 5, then 9

|________X___________|

HTS-3: After clearing every stop

\e[3g     # clear every tab stop
\e[1;12H
\eH
\e[1;1H
\tX

|___________X________|

HTS-4: The 8-bit form, sent as UTF-8

\e[3g      # clear every tab stop
\e[1;12H
\u{88}     # U+0088 is HTS in 8 bits; ignored
\e[1;1H
\tX        # no stop was set

|___________________X|