org-track-ordered-property-with-tag

org-track-ordered-property-with-tag is a variable defined in `org.el'.
Its value is

nil

Documentation:
Should the ORDERED property also be shown as a tag?
The ORDERED property decides if an entry should require subtasks to be
completed in sequence. Since a property is not very visible, setting
this option means that toggling the ORDERED property with the command
`org-toggle-ordered-property' will also toggle a tag ORDERED. That tag is
not relevant for the behavior, but it makes things more visible.

Note that toggling the tag with tags commands will not change the property
and therefore not influence behavior!

This can be t, meaning the tag ORDERED should be used, It can also be a
string to select a different tag for this task.

You can customize this variable.