In the debian/control stanza for the given package, a stronger dependency field implies one of the dependencies in a weaker dependency field. In other words, the Depends field of the package requires that one of the packages listed in Recommends or Suggests be installed, or a package is listed in Recommends as well as Suggests.
Current versions of dpkg-gencontrol will silently fix this problem by removing the weaker dependency, but it may indicate a more subtle bug (misspelling or forgetting to remove the stronger dependency when it was moved to the weaker field).
Refer to Debian Policy Manual section 7.2 (Binary Dependencies -
Pre-Depends) for details.