The nishan sahib is the Sikh flag, flown from a tall pole outside every gurdwara, and it marks the place and proclaims the presence of the community.
The pole and the emblem
The flag is triangular and is flown from a tall pole clad in cloth of the same colour and topped with a steel emblem of the double-edged sword, the khanda, so the whole standing structure, pole, cloth and emblem, forms the sign. It is set high so that it can be seen from a distance, and it announces that the building beneath it is a gurdwara and that the community and the scripture are present there, functioning as a landmark and a declaration at once. The colour, most often a deep saffron or, in some traditions, blue, is itself a mark of the faith.
Renewed each year
The cloth of the nishan sahib is ceremonially replaced, in many places once a year at a spring festival, when the pole is lowered, the old cloth removed, the pole washed, and fresh cloth wrapped and the flag raised again, an occasion of gathering and devotion. This renewal keeps the sign bright and makes its raising a communal act. The flag thus does more than mark a building: it declares a presence, it serves as a visible centre for the community, and its annual renewal is one of the observances by which a congregation affirms its identity and its attachment to the gurdwara over which the nishan sahib flies.