7. If the visa is issued
Possession of a short-stay visa is a necessary but not sufficient condition for entering the Schengen Area. When you cross the border of the Schengen Area, the border police may require you to show the supporting documents you submitted to obtain your visa.
Вот откуда уши растут.
A mere possession of a visa does not confer an automatic right of entry to the country. The holder of visa can be requested to present proof that he/she fulfils the entry conditions at the external border, as provided for in Article 5 of the Schengen Borders Code. If the circumstances under which a visa was issued have changed, border authorities may refuse entry and cancel the visa. A visa may also be cancelled if it is subsequently established that the data submitted during the visa issuing procedure were incorrect or that important facts were concealed.