# Placeholder value filtering
<a name="resource-matching-placeholder-filtering"></a>

Resource matching automatically ignores identifier values that are:
+ all zeros (for example, `0`, `000000000`, `00-000-0000`);
+ common placeholders, case-insensitive (`unknown`, `n/a`, `na`, `none`, `null`, `unassigned`, `pending`, `temp`, `test`);
+ fewer than three characters; or
+ empty or whitespace only.