Double backslashes are a prefix to a server name (hostname) in the universal naming convention (see
UNC). For example,
\\a5\c\expenses is the path to the EXPENSES folder on the C: drive on server A5.
They are also used in several programming languages to reference a single backslash for display and printing, because a single backslash is used to define hexadecimal numbers. For example,
\\stage\\cd\\pictures means display or print
\stage\cd\pictures. See
backslash.