Используйте :h select-mode, и вы увидите описание режима выбора. Здесь выдержка:
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8. Select mode *Select* *Select-mode*
Select mode looks like Visual mode, but the commands accepted are quite
different. This resembles the selection mode in Microsoft Windows.
When the 'showmode' option is set, "-- SELECT --" is shown in the last line.
Entering Select mode:
- Using the mouse to select an area, and 'selectmode' contains "mouse".
'mouse' must also contain a flag for the current mode.
- Using a non-printable movement command, with the Shift key pressed, and
'selectmode' contains "key". For example: <S-Left> and <S-End>. 'keymodel'
must also contain "startsel".
- Using "v", "V" or CTRL-V command, and 'selectmode' contains "cmd".
- Using "gh", "gH" or "g_CTRL-H" command in Normal mode.
- From Visual mode, press CTRL-G. *v_CTRL-G*
...
*gh*
gh Start Select mode, characterwise. This is like "v",
but starts Select mode instead of Visual mode.
Mnemonic: "get highlighted".
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