The Member States shall require that packages of basic seed and certified seed of all categories be sealed officially or under official supervision in such a manner that they cannot be opened without damaging the sealing system or without leaving evidence of tampering on either the official label provided for in Article 10 (1) or the package.

In order to ensure sealing, the sealing system shall comprise at least either the abovementioned label or the affixing of an official seal.

The measures provided for in the second subparagraph above shall not be necessary where a non-reusable sealing system is used.

In accordance with the procedure laid down in Article 21, it may be established whether a particular sealing system complies with the provisions of this paragraph.

Packages which have been officially sealed shall not be resealed, whether one or more times, except officially F1or under official supervision. If packages are resealed, the fact of resealing, the most recent date of resealing and the authority responsible therefor shall be stated on the label required under Article 10 (1).

Member States may provide for exceptions to paragraph 1 in the case of small packages F4sealed in their own territory. Conditions relating to these exceptions may be determined in accordance with the procedure laid down in Article 21 .