Sharepoint internal names can only include letters/numbers and underscores.
Any other character needs to be encoded using this scheem:
Convert the character's ascii representation to a four digit hex number, prefixed with 'x' and surrounded by underscores.
| Character | Encoded As |
|---|---|
(space) |
_x0020_ |
! |
_x0021_ |
" |
_x0022_ |
# |
_x0023_ |
$ |
_x0024_ |
% |
_x0025_ |
& |
_x0026_ |
' |
_x0027_ |
( |
_x0028_ |
) |
_x0029_ |
* |
_x002a_ |
+ |
_x002b_ |
, |
_x002c_ |
- |
_x002d_ |
. |
_x002e_ |
/ |
_x002f_ |
: |
_x003a_ |
; |
_x003b_ |
< |
_x003c_ |
= |
_x003d_ |
> |
_x003e_ |
? |
_x003f_ |
@ |
_x0040_ |
\ |
_x005c_ |
^ |
_x005e_ |
(backtick) |
_x0060_ |
{ |
_x007b_ |
| ` | ` |
} |
_x007d_ |
~ |
_x007e_ |
I don't know how a literal "_x" is encoded, but no doubt there is a convention, such as encoding literal _x as _xx (thus a _x(x)+ decodes to _($1) )(But this is just speculation.)