This package provides an user interface for making LaTeX cross-references flexibly, while allowing to have them checked for consistency with the document structure as typeset. Statements such as above, on the next page, previously, can be given to \zcheck in free-form, and a set of checks can be specified to be run against a given label, which will result in a warning at compilation time if any of these checks fail. \zctarget and the zcregion environment are also defined as a means to easily set label targets to arbitrary places in the text which can be referred to by \zcheck.