enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
the n-th prior value of that ref. For example 'master@\{1\}'
is the immediate prior value of 'master' while 'master@\{5\}'
is the 5th prior value of 'master'. This suffix may only be used
immediately following a ref name and the ref must have an existing
enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
the n-th prior value of that ref. For example 'master@\{1\}'
is the immediate prior value of 'master' while 'master@\{5\}'
is the 5th prior value of 'master'. This suffix may only be used
immediately following a ref name and the ref must have an existing