Significance - Travellers Accounts
One of the very earliest accounts of Sikhs in a European newspaper appeared in a London Times 1801 issue and interestingly references a Nishan Sahib. The news report recounts the desecration of a Nishan Sahib by a group of Hindu Fakirs and the ensuing revenge of the Sikhs.
Saturday, October 17, 1801
We have received a Private Letter by the late Overland Dispatch from Bombay, by which we are informed, that the Seiks threaten the whole tribe of Fakeers with immediate hostility, in consequence of some supposed transgression on the part of the Fakeers.
It appears that the Seiks has usurped an authority of erecting a flag in Rohilchund, which the Fakeers pulled down, and drove away the little Seik establishment. They maintained peaceful possession of the place till the arrival of about 12 or 14,000 Seikh horsemen, when they hoisted the distinguishing flag of their sect. Here they attacked the Fakeers with swords, spears and fire-arms, and drove them with irresistible fury.
Having discharged their pieces within a few paces, they rushed upon those unfortunate pilgrims that came in their way, and having slaughtered a great number, pursued the remainder, until, by flight to the hills, or by swimming the river, they escaped the revenge of their pursuers. Many were drowned, and of those who endeavored to escape to the heights, numbers were plundered; but none who had not the habit of a Fakeer were in the least hurt.
Accounts agree, that the Fakeers lost about 2000 men killed, among whom was one of their Chiefs, and they had many wounded. The contest was very unequal, for the Seiks were all mounted, and attacked in the night. The Fakeers are bending their march in a westerly course, directly from the Seiks. The number which had crowed in the river side, when they were obliged to remain some time, were fearful of the approach of day, and in dreadful alarm, from the expectation of another visit from the Seiks. The hostile conduct of the Seiks was purely in revenge against the tribes of Fakeers, for disrespect and contempt of their flag.
The incredible voracity of the Sikhs anger at what they perceived as a major transgression and insult to their faith caused by the Hindu Fakirs taking down their Nishan Sahib reveal their strong reverence for the sacred banner at their places of worship.
An account of the great Sarbar Khalsa of 1762 when Sikh groups called misls gathered at Amritsar mentions that one misl had the important duty of caring for the Sikh banner while another played an important role at the meeting carrying a battle axe of significance to the Sikhs.
The assembly or ceremony, called Sarbat Kalsa, was held with great rejoicing. After every Sikh had bathed in the holy purifying water, they met to hold a Gurmatta or council, for the organization of the Sikh confederacy. Their proceedings were carried on with the proper forms, the Aluwala Sirdar carried the battle-axe of the people, called Kalal; the chief of the Nishanwala Misal carried the banner of the faith, or Nishan.
Travels in Kashmir and the Panjab
Baron Charles Hugel, translated from German with Notes by Major T.B. Jervis, 1845,
The Nishanwalian confederacy composed of Sikhs from Ferozpur and headquartered at Ambala had the duty of being the foremost bearers of the Sikh banner and their name reflected this important duty.  The other group mentioned was the Ahluwalia confederacy. Mata Sundri, Guru Gobind Singh's widow had blessed it's leader Jassa Singh Ahluwalia with a mace belonging to the Guru  and this weapon seems to have become an important Sikh relic of respect at the Sarbat Khalsa meeting.
1. A History & Guide to The Golden Temple,Amritsar, Sodhi Hazara Singh, pub. Messrs Partap Singh Sunder Singh, Amritsar, 1938