# Case sensitivity

[](https://help.qlik.com/talend/en-US/talend-data-catalog/Content/developer-guide/metadata-query-language-mql/case-sensitivity.htm)

The following are case-insensitive:

* Filter types except for system attribute names, profile attribute names, custom relationship names, custom attribute names, and UDP names used as filter types. For example,

  > text = "Customer"

  is equivalent to "TEXT = "Customer"".

* Operators. For example, = all is equivalent to = ALL, before is equivalent to BEFORE, or is equivalent to OR, etc.

* Search properties used in the WITHIN clause of the text or semantic\_search\_text filters.

* Filter values

* Order by

* Facet values

The following are case-sensitive:

* The FROM clause. For example, /Published is not equivalent to /published.

* System attribute names, profile attribute names, custom attribute names, custom relationship names, and UDP names used in the SELECT list, ORDER BY fields, or as filter types in the WHERE clause. For example,

  > Security level

  is not equivalent to

  > security level

  .