A language game (also called secret language or ludling or argot) is a system of manipulating spoken words to render them incomprehensible to the untrained ear.
 Language games are used primarily by groups attempting to conceal their conversations from others.
 Some common examples are Pig Latin; the Gibberish family, prevalent in the United States and Sweden; and Verlan, spoken in France.
Hijra Farsi (Urdu: ) is a secret language spoken by South-Asian hijra and koti communities.
 Hijras are a marginalized transgender community that lives in sequestered groups in many cities of India and Pakistan.
 The language, also known as "Koti Farsi", is spoken by the hijra community throughout Pakistan and North India (except West Bengal).
 The language is based on Hindustani and not Farsi, as suggested by the name.
 The sentence structure is similar to Urdu, but noticeable distinctions exist.
 Even though the language is not actually based on Persian (Farsi), the hijras consider the language to be related to the language of the Mughal Empire, which they associate with the origin of hijra identity.
 Hijra Farsi is most similar to Hindi, but is not intelligible to Hindi speakers due to distinctive intonation and a large amount of distinctive vocabulary.
Romano-Greek (also referred to as Hellenoromani; ) is a nearly extinct mixed language (referred to as Para-Romani in Romani linguistics), spoken by the Romani people in Greece that arose from language contact between Romani speaking people and the Greek language.
 The language is expected to be a secret language spoken in Thessaly and Central Greece Administrative Unit.
 Typologically the language is structured on Greek with heavy lexical borrowing from Romani.
 Related variants of this language are Dortika.
 Dortika is a secret language spoken mainly in Athens by traveling builders from Eurytania Prefecture.
 In both cases, the languages are most likely not native to their speakers.
Hindustani vocabulary, also known as Hindi-Urdu vocabulary, like all Indo-Aryan languages, has a core base of Sanskrit, which it gained through Prakrit.
 As such the standardized registers of the Hindustani language (Hindi-Urdu) share a common vocabulary, especially on the colloquial level.
 However, in formal speech, Hindi tends to draw on Sanskrit, while Urdu turns to Persian and sometimes Arabic.
 This difference lies in the history of Hindustani, in which the Khariboli dialect started to gain more Persian words in urban areas (such as Lucknow and Hyderabad), under the Delhi Sultanate; this dialect came to be termed Urdu.
 The original Hindi dialects continued to develop alongside Urdu and according to Professor Afroz Taj, "the distinction between Hindi and Urdu was chiefly a question of style.
 A poet could draw upon Urdu's lexical richness to create an aura of elegant sophistication, or could use the simple rustic vocabulary of dialect Hindi to evoke the folk life of the village.
 Somewhere in the middle lay the day to day language spoken by the great majority of people.
 This day to day language was often referred to by the all-encompassing term "Hindustani"."
 In Colonial India, Hindi-Urdu acquired vocabulary introduced by Christian missionaries from the Germanic and Romanic languages, e.g. "pādrī" (Devanagari: पादरी, Nastaleeq: پادری) from "padre", meaning pastor.
 When describing the state of Hindi-Urdu under the British Raj, Professor Śekhara Bandyopādhyāẏa stated that "Truly speaking, Hindi and Urdu, spoken by a great majority of people in north India, were the same language written in two scripts; Hindi was written in Devanagari script and therefore had a greater sprinkling of Sanskrit words, while Urdu was written in Persian script and thus had more Persian and Arabic words in it.
 At the more colloquial level, however, the two languages were mutually intelligible."
 After the partition of India, political forces within India tried to further Sanskritize Hindi, while political forces in Pakistan campaigned to remove Prakit/Sanksrit derived words from Urdu and supplant them with Persian and Arabic words.
 Despite these government efforts, the film industry, Bollywood continues to release its films in the original Hindustani (Hindi-Urdu) language, easily understood and enjoyed by speakers of both registers; in addition many of the same television channels are viewed across the border.
Sangirese or Sangihe people are one of the native people to the Sangir Islands in the northern chain of islands in Sulawesi and the southern part of Mindanao.
 Their native language is Sangirese language, while Sasahara language is a secret language spoken among Sangirese sailors or pirates.
 The Sangirese people are fishermen and nutmeg growers in their home areas and also work as wage labourers in industrial crops enterprises in Bolaang Mongondow Regency and Minahasa Regency.
In South Asia, a Hijra (for translations, see 0.3em ) is a transgender individual who was assigned male at birth.
 They are also known as "Aravani", "Aruvani" or "Jagappa".
 In many languages of India, especially outside North-West India, other terms are used such as "Thirunangai" in Tamil or "chhakka" in Kannada.
Caló (] ; ] ; ] ; ] ) is a language spoken by the Spanish and Portuguese Romani.
 It is a mixed language (referred to as a Para-Romani language in Romani linguistics) based on Romance grammar, with an adstratum of Romani lexical items through language shift by the Romani community.
 It is often used as an argot, a secret language for discreet communication amongst Iberian Romani.
 Catalan, Galician, Portuguese, and Spanish "caló" are closely related varieties that share a common root.
Rotvælsk was a secret language (also known as a cant or cryptolect) that was spoken in Denmark from early modern times until the turn of the 20th century.
 Rorvælsk was also known under several other names.
 It is now extinct.
 Rotvælsk was used by a social group known as Natmændsfolk who did simple craftsmanship, demeaning and unclean work or panhandled to survive.
 Both the social group and the language changed through the centuries, but remained associated with crime, loose morals, poverty and low social status in the eyes of the surrounding population.
 The social group and their language have often been confused with Romani people and the Romani language, though they do not seem to have had a different ethnic origin than most danes at that time.
Bengali ( ), also known by its endonym Bangla ( ; বাংলা ] ), is an Indo-Aryan language spoken in the Indian Subcontinent.
 It is the national and official language of the People's Republic of Bangladesh, and the official language of some eastern and north-eastern states of the Republic of India, including West Bengal, Tripura, Assam (Barak Valley) and Andaman and Nicobar Islands.
 It is also one of the 22 scheduled languages of India.
 With 205 million speakers, Bengali is the seventh most spoken native language in the world by population.
 Dictionaries from the early 20th century attributed slightly more than half of the Bengali vocabulary to native words (i.e., naturally modified Sanskrit words, corrupted forms of Sanskrit words, and loanwords from non-Indo-European languages), about 30 percent to unmodified Sanskrit words, and the remainder to foreign words.
 Dominant in the last group was Persian, which was also the source of some grammatical forms.
 More recent studies suggest that the use of native and foreign words has been increasing, mainly because of the preference of Bengali speakers for the colloquial style.
 Today, Bengali is the primary language spoken in Bangladesh and the second most widely spoken language in India.
Minderico, also known as "Piação do Ninhou" (the language of Minde), was originally a sociolect or a secret language spoken by textile producers and traders in the freguesia (civil parish) of Minde (Alcanena, Portugal).

Question: Hijra Farsi (Urdu: ) is a secret language spoken by South-Asian hijra and which communities?
Answer: koti