In general, the safest keys to use for the {lhs} (left-hand
side) of mappings are the F keys. Almost everything else
already has a function in Vim. Among
Worth knowing. Thanks. What about when using a leader such as
"," or "/" ?
The comma does a reverse-search of the last thing you searched
for using t/T/f/F which many folks don't use (so they use it for
leader), but I use regularly.
:help ,
:help ;
The forward slash does searching...something used quite regularly.
:help /
I think the only key that isn't reserved (in that Vim doesn't
already have meaning assigned to it) is the backslash, which is
what the leader defaults to (so in a way, it is used...but only
for the purpose you describe). I tend to use the default
backslash as my leader (on those rare occasions I use the leader)
because I know it's available and it's vim-portable.
One other candidate might be the underscore, though it's a
shifted key which makes it a little more difficult, it is usually
in a pretty predictable place (unlike the backslash/pipe key
which I find all over the keyboard depending on whose machine I'm
using...makes typing DOS file-paths a pain).
Just my $0.02
-tim