Non 7-bit ASCII characters in search filters must be replaced with a representation of the character, where each byte of the UTF-8 encoding is preceded by a backslash. In UTF-8, characters are represented by a hexadecimal code for each byte.
For example, the character é has UTF-8 representation c3a9. Thus, in a search filter, you represent é as \\c3\\a9. So, to search for cn=Véronique Martin:
ldapsearch -h myServer -b "dc=example,dc=com" "(cn=V\\c3\\a9ronique Martin)"
The special characters listed in Table 13–7 must also be represented in this fashion when used in search filters.
Table 13–7 Special Characters in Search Filters| Special character | Value With Special Character | Example Filter | 
|---|---|---|
| * | Five*Star | (cn=Five\\2aStar) | 
| \\ | c:\\File | (cn=\\5cFile) | 
| () | John (2nd) | (cn=John \\282nd\\29) | 
| null | 0004 | (bin=\\00\\00\\00\\04) | 
When using a DN in any part of Directory Server, you must escape commas and certain other special characters with a backslash (\\). If you are using a DN in a search filter, the backslash used for escaping special characters in DNs must be represented by \\5c. For example:
DN: cn=Julie Fulmer,ou=Marketing\\,Bolivia,dc=example,dc=com
DN in a search filter: ldapsearch -h myServer -b "dc=example,dc=com" "(manager=cn=Julie Fulmer,ou=Marketing\\5c,Bolivia,dc=example,dc=com)"