When you look at a MAC address on a Cisco router or switch, it is displayed as 4 digits dot 4 digits dot 4 digits.  Windows displays them with dashes between each byte and Linux colons between each byte.  Many people edit mac addresses to change them to the Cisco format in order to paste them into a Cisco config.  You can just remove the dashes or paste with colons and Cisco devices will accept the MAC address; however, they will not take dashes as delimiters.