decis execut committe decemb procedur appli articl convent implement schengen agreement sch rev execut committe regard articl convent implement schengen agreement regard articl abovement convent decid document sch rev procedur appli articl convent approv principl procedur set respect contract parti wish invok derog claus provid articl convent temporarili reinstat check intern border ostend decemb chairman johan vand lanott procedur applic articl convent sch rev quot articl intern border cross point check person carri public polici nation secur requir contract parti consult contract parti decid limit period nation border check situat carri intern border public polici nation secur requir action contract parti concern measur earliest opportun inform contract parti thereof quot object measur provid schengen convent avoid invok articl reinstat check remain measur except procedur prior consult articl sentenc state contempl reinstat check intern border short term send notif state inform ground plan measur state question event constitut threat public order nation secur extent plan measur state question check reinstat border area durat plan measur state date measur appli consult probabl durat request consult state measur expect state individu collect adopt avoid reinstat check check reinstat supplement measur request state notif decis member execut committe central group gener secretariat accord articl presid swiftli conven meet execut committe possibl preced central group meet plenari restrict session conduct consult state extraordinari meet held execut committe meet plan place futur case item ad agenda decis reinstat border check continu appli consult phase request state inform abovement recipi date condit applic measur connect articl agreement cross border polic cooper border author request state inform border author state concern expedit reaction field procedur decis articl sentenc state deem reinstat check immedi maintain public order nation secur send notif state element list point ground extent probabl durat measur criteria refer point appli recipi notif bilater talk state request assist cooper state take circumst account execut committe meet conven notif decis procedur extens return normal state appli procedur articl confirm date check lift time shortli submit report implement decis state deem durat valid initi decis extend notifi decis effect accord procedur point