Whenever possible, Novi follows QuickBooks' lead when setting allowable characters and character count limits on fields. We do this to reduce the chance of sync errors and to ensure the smoothest user experience possible between the two platforms.
These characters are specifically not supported:
The 'Tab' character (Generally speaking, many text editors will simply insert 2 or 4 spaces when the 'Tab' key is pressed. This is different than the actual 'Tab' character)
Newline (This is when there is a new line within the text entered for the field)
The characters that QuickBooks generally supports follow an ISO specification called "ISO-8859-1". A list of these characters can be found at the link below but a short description is basically any well-known character that is not an emoji.
View ISO-8859-1 character set: https://cs.stanford.edu/people/miles/iso8859.html#ISO
View which languages are fully covered and, for ones that aren't fully covered, which characters can be substituted: https://en.wikipedia.org/wiki/ISO/IEC_8859-1#Modern_languages_with_complete_coverage
QuickBooks Customer API Documentation. Look under the "Business Rules" section.