One rule per line
Operators are = > < >= <= !=
Simple presence of the field is assurred via = operator. Field can therefore have any value.
Not presence of the field is assurred via ! operator.
Possible info fields are listed on FAQ page

Example:
map=*dust2* and max_players>=32

Example:
map=*de_nuke*
map=de*
map=*dust2*

Example:
vac=true

Example:
vac=1

Example:
bots=0