The IT Assets Database was replaced by the IT Admins CMDB and is EOL / End of Life, no further development will be done on this project.
MAC address search is nothing else then a central view over all possible MAC address source tables, combining them and linking the information back to this search view.
It is an issue that MAC addresses are so variable in the way they made available and probably put in to the database as well. Due to this fact, the search view on the SQL server shows you the original field value, then tries to format it Cisco like ####.####.#### and then tries to remove all other usual delimiters like spaces, dots, colons and dashed to make the MAC available in a third field that should be as plain as possible. This allows you to search rather quick and with a normalized format, where possible.