The most common type of reference sheet I use, is just a table of values that don't have a real meaning, for example I have bookmarked a table of ANSI terminal

The most common type of reference sheet I use, is just a table of values that don't have a real meaning, for example I have bookmarked a table of ANSI terminal escape codes, and this table of Bash string operations: http://tldp.org/LDP/abs/html/refcards.html#AEN22587 http://tldp.org/LDP/abs/html/refcards.html#AEN22587