Hazrat Sheikhul Hadith Moulana Zakariyya Khandelwi Rahmatullahi Alaihi writes in Aap Beti, Volume 4 & 5, pg 152 (english translation) under chapter 10: My Uncle Maulana Muhammed Ilyaas Rahmatullahi ‘Alaihi:
Once my uncle told me: “Some of our friends are of the opinion that when our jamaats proceed on ghusht, they should carry a short banner (flag) with them. What do you think? “
I replied: “Most definitely not.“
He asked: “And why not?”
I said: “Your jamaats are going out to call people to the Salaah and gather the people in the Masjid. And according to the clear texts (of Quraan and Hadith) the use of a banner for Salaah is rejected.”
He replied: “May Allah reward you well. This issue is put off.”