All appeals are dismissed.

The costs of appeal are assessed against the plaintiffs.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. In order for an administrative disposition to be deemed null and void as a matter of course, the mere fact that there is an illegality in the disposition is insufficient. The defect must be objectively apparent and serious in violation of the important part of the law. In determining whether the defect is significant and obvious, the purpose, meaning, function, etc. of the law shall be examined from a teleological perspective and reasonable consideration of the specificity of the specific case itself should be

(2) The judgment of the court below and the judgment of the court of first instance cited by the court below on June 24, 2005 (see, e.g., Supreme Court Decision 2004Du10968, Jun. 24, 2005) acknowledged the facts as stated in its holding after compiling the adopted evidence. The defendant dismissed all the plaintiffs' claims seeking confirmation of invalidity of each of the above dispositions on the grounds that the defendant's decision cannot be deemed to have a serious and obvious defect in violating the important parts of the laws and regulations in the decision of the Incheon Urban Management Planning (Designation, etc. of the B Urban Development Zone) as of May 8, 2006, the decision of the Incheon Urban Management Planning (Designation, etc. of the B Urban

In light of the above legal principles and records, we agree with the court below's measures are just, and there is no error of law such as misunderstanding of legal principles as argued in the Grounds for Appeal.

3. Therefore, all appeals are dismissed, and the costs of appeal are assessed against the losing party. It is so decided as per Disposition by the assent of all participating Justices on the bench.