-i or --ignore-case
Causes searches to ignore case; that is, uppercase and lowercase are considered identical. This
option is ignored if any uppercase letters appear in the search pattern; in other words, if a
pattern contains uppercase letters, then that search does not ignore case.
-R or --RAW-CONTROL-CHARS
Like -r, but only ANSI "color" escape sequences are output in "raw" form. Unlike -r, the screen
appearance is maintained correctly in most cases. ANSI "color" escape sequences are sequences of
ESC [ ... m
where the "..." is zero or more color specification characters For the purpose of keeping track of
screen appearance, ANSI color escape sequences are assumed to not move the cursor. You can make
less think that characters other than "m" can end ANSI color escape sequences by setting the
environment variable LESSANSIENDCHARS to the list of characters which can end a color escape
sequence. And you can make less think that characters other than the standard ones may appear
between the ESC and the m by setting the environment variable LESSANSIMIDCHARS to the list of
characters which can appear.
-xn,... or --tabs=n,...
Sets tab stops. If only one n is specified, tab stops are set at multiples of n. If multiple
values separated by commas are specified, tab stops are set at those positions, and then continue
with the same spacing as the last two. For example, -x9,17 will set tabs at positions 9, 17, 25,
33, etc. The default for n is 8.