<p>The process name may contain one or more occurrences of <tt>%s</tt>. If you do this, then the pattern must be a regular expression and be prefixed with ~. For each <tt>%s</tt> in the description, the expression has to contain one "group". A group is a subexpression enclosed in brackets, for example <tt>(.*)</tt> or <tt>([a-zA-Z]+)</tt> or <tt>(...)</tt>. When the inventory finds a process matching the pattern, it will substitute all such groups with the actual values when creating the check. That way one rule can create several checks on a host.</p><p>If the pattern contains more groups then occurrences of <tt>%s</tt> in the service description then only the first matching subexpressions are used for the service descriptions. The matched substrings corresponding to the remaining groups are copied into the regular expression, nevertheless.</p><p>As an alternative to <tt>%s</tt> you may also use <tt>%1</tt>, <tt>%2</tt>, etc. These will be replaced by the first, second, ... matching group. This allows you to reorder things.