least, it is not clear whether the relation is genetic, or perhaps rather one of borrowing compounded by extensive incorporation of a shared South Asian gestural base). There is disagreement whether these related varieties should be considered separate languages. Woodward (1992a) researched the vocabulary of the sign language varieties in Karachi (Sindh, Pakistan), Delhi (NCT, India), Bombay (Maharashtra, India), Bangalore (Karnataka, India) and Calcutta (West Bengal, India). He found cognacy rates of 62–71% between the Karachi vocabulary on the one hand and the four Indian vocabularies on the other, and concluded that 'sign language varieties in India and Pakistan are distinct but closely related language varieties belonging to the same language family'. Woodward (1993) expanded on his 1992 research by comparing the results from India and Pakistan with new data from Nepal, tentatively concluding that the sign language varieties of India, Pakistan, Nepal and probably also Bangladesh and Sri Lanka are so closely related that they may, in fact, constitute a single sign language. Zeshan (2000), based on her own research in Karachi and New Delhi concluding that their grammar was identical and there were only small differences in vocabulary, proposed that the Indian and Pakistani varieties constitute a single language, introduced the term 'Indo-Pakistani Sign Language' and emphatically rejected the notion of separate Indian and Pakistani sign languages. The ISO 639-3 standard categorises these varieties as three separate sign languages in India and Bangladesh, Pakistan, and Nepal. Ethnologue (2016), which follows the ISO standard, acknowledges the relatedness of these varieties as well as the controversy over whether they are one language or many. They identify the following dialects within India: Bangalore-Chennai-Hyderabad Sign Language, Mumbai-Delhi Sign Language and Kolkata Sign Language. Johnson and Johnson (2016) argue that the varieties used in Kolkata and Bangladesh are distinct from that used in Delhi, and probably also from each other. While the sign system in IPSL appears to be largely indigenous, elements in IPSL are derived from British Sign Language. For example, most IPSL signers nowadays use fingerspelling based on British Sign Language fingerspelling, with only isolated groups using an indigenous devanagari-based fingerspelling system (for example, Deaf students and graduates of the school for the deaf in Vadodara/Baroda, Gujarat). In addition, more recently contact with foreign Deaf has resulted in rather extensive borrowing from International Signs and (either directly or via International Signs) from American Sign Language. A small number of the Deaf