The article draws a parallel with the recognition of the self-government of the City of London when the Heralds have to request, and are fmgeanted, permission to enter that jurisdiction at Temple Bar to proclaim a new monarch or a peace treaty. Another parallel may well be the custom in most Anglican cathedrals, but not, as I understand it, traditionally at Canterbury, for the new diocesan to knock with their crosier on the west door to require admission to be enthroned. At this recognition of the autonomy of the Dean and Chapter the doors are thrown open and the Bishop enters and proceeds to symbolically take possession of his see and its cathedral church.
A further analogy is the traditional Catholic practice on Palm Sunday of the processional cross being employed to knock on the principal door of the church to demand admission for the Palm procession.
Neither of these are about excluding anyone so much as in the case of the enthronement recognising sel-government and in the instance of Palm Sunday the authority of Christ over Jerusalem and the Tenple.