Can I use foreign characters?

You can put some European characters in to your application form that are not in the English alphabet, however, UCAS are quite particular about the way candidates format their personal statement. Backslashes, curly brackets, and angled quote marks are a no-no, as are a number of other characters. 

UCAS provides a comprehensive character substitution list for characters that cannot be used.

Don't worry about indenting paragraphs (which will just waste characters anyway), or using bold, italics, underlining, etc. as this will just be removed when you paste it into the UCAS form.