2.2.3 LMHOSTS File Syntax
There can be one entry per line. An entry consists of an IPv4 address and a name, which can be either a computer name or a NetBIOS service name.
Comment lines in the LMHOSTS file start with the pound sign (#).
Comments can start after the start of a line, with the pound sign (#), and without the use of LMHOSTS keywords. (See the LMHOSTS keywords in the table that follows.)
The pound sign (#) can also denote LMHOSTS keywords listed in the table that follows.
ComputerName Entries consist of an IPv4 address and a NetBIOS computer name where the name is 1 to 15 characters in length. A computer name can be used to either: 1) resolve a name to an IP address, or 2) resolve a NetBIOS service name to an address. Example: "18.104.22.168 emailsrv1".
ServiceName entries consist of an IPv4 address and a NetBIOS service name that specifies a 16-byte name where the last byte indicates the type of the service and bytes 1 to 15 specify ComputerName, padded at the end with blanks to the 15th byte:
22.214.171.124 "ComputerName \0x03" where the last byte is specified in hex.
Entry Names are not case-sensitive.
The LMHOSTS file has an implementation-specific file location.<4>