Amul, India's best-known brand of milk, butter and other dairy products, has gone to war against the country's five trademark registry offices for allowing makers of underwear, tractors and other products to use the name.A case has been filed in the Gujarat High Court against the registries in Delhi, Mumbai Chennai and Ahmedabad for allowing the registration of Amul or similar sounding names as trademarks.This is despite Amul having successfully fought against companies adopting the brand A decision on Amul's trademark case will have implications for all of them, legal experts said.According to court documents seen by ET, the latest petition alleges that the trademark offices have continued to allow registration of the name or some mark “deceptively similar” to it even after Amul was included in the Well-Known Trademark list in May 2015 by the Intellectual Property Appellate Board (IPAB), which includes the trademark offices. The list is maintained by the trademark offices on their website to ensure that no other entity launches products with similar brand names or logos. It includes about 70 brands including Ford, Toyota, Google, Nestle, Microsoft and Pepsi.The name is indelibly associated with the Gujarat milk cooperative movement and the father of India's White Revolution Verghese Kurien, thanks to the iconic ads for its salted butter that feature the Amul girl and the catchphrase "utterly butterly delicious."Amul also sells ice-cream, cheese, chocolates, health drinks, ghee, paneer, and other dairy products.The trademark has been owned by the Kaira District Co-Operative Milk Producers Union Ltd (KDCMPU), also known as the Amul dairy, since 1955.The Gujarat Cooperative Milk Marketing Federation Ltd (GCMMF), an apex marketing organisation set up by six cooperatives to sell products under the Amul brand name, got the rights to use the name in 1973.Gujarat Cooperative Milk Marketing Federation now has 17 milk cooperatives under its umbrella and posted Rs 27,085 crore in FY17 sales, up 18% from the previous year.The case has been filed by Amul dairy and GCMMF.Gujarat Cooperative Milk Marketing Federation managing director RS Sodhi didn't respond to queries. Emails sent to the trademark registry offices also didn't meet with any response.The case alleges that companies are advertising products under the Amul brand name."The applicants submit that they have written letters to the respondents (trademark office) requesting them not to accept advertisement applications by imitators," the court document read."However, despite such requests the respondents continue to accept such advertisements."In 2013, Amul stopped a West Bengal based milk cooperative union from using Imul as its brand name. IPAB had ruled that this was deceptively similar to Amul.It also locked horns with Amul Tractors, a Rajkot-based company, and Amul Hosiery, a Mumbai-headquartered company, for the brand name and logo.