Some characters must be treated specially, using character entities:
|"||"||double quotation mark|
Any other characters which are not on your keyboard can either be entered as numeric
entities (see, eg, http://www.tedmontgomery.com/tutorial/HTMLchrc.html) or
using UTF-8. How you enter UTF-8 on your keyboard depends on your application or operating
system. oXygen, for example, has a facility
[Edit/Enter from Character Map] to
let you enter characters which are not on the keyboard.