Question: What is the purpose of the society founded in a city also familiarly known as Thessalonica or Salonica?

Context articles: Boylan-Haven-Mather Academy
Tony Jannus
Pittsburgh Geological Society
Armistice of Salonica
Handel and Haydn Society
Edward Faragher
Carrier Sekani Tribal Council
Thessaloniki
Society for Macedonian Studies
The Philomathean Society (Phillips Academy)

Boylan-Haven-Mather Academy, more familiarly known as “Mather Academy,” was a private African American boarding school in Camden, South Carolina.
 Its name reflects four schools founded and merged in South Carolina, Georgia and Florida by the Women's Home Missionary Society of the Methodist Episcopal Church to educate former slaves and their descendants.
 Boylan-Haven-Mather Academy closed in 1983.
 Among its graduates/students were U.S. Congressman James E. Clyburn (D-SC), major league baseball pioneer Larry Doby, businessman E. Perry Palmer, childcare advocate Frieda Mitchell, "Dean of the CIAA" coach Eddie C. McGirt, and civil rights attorney John Roy Harper II.
Antony Habersack Jannus, more familiarly known as Tony Jannus (July 22, 1889 – October 12, 1916), was an early American pilot whose aerial exploits were widely publicized in aviation's pre-World War I period.
 He flew the first airplane from which a parachute jump was made, in 1912.
 Jannus was also the first airline pilot, having pioneered the inaugural flight of the St. Petersburg–Tampa Airboat Line on January 1, 1914, the first scheduled commercial airline flight in the world using heavier-than-air aircraft.
 The "Tony Jannus Award", created to perpetuate his legacy, recognizes outstanding individual achievement in the scheduled commercial aviation industry and is conferred annually by the Tony Jannus Distinguished Aviation Society founded in Tampa, Florida, in 1963.
The Pittsburgh Geological Society, more familiarly known as the PGS, was founded in 1945.
 Its purpose is to serve the professional interest of the society's membership.
The Armistice of Salonica (also known as the Armistice of Thessalonica) was signed on 29 September 1918 between Bulgaria and the Allied Powers in Thessaloniki.
 The convention followed after a request by the Bulgarian government on 24 September asking for a ceasefire.
 The armistice effectively ended Bulgaria's participation in World War I on the side of the Central Powers and came into effect on the Bulgarian front at noon on 30 September.
 The armistice regulated the demobilization and disarmament of the Bulgarian armed forces.
The Handel and Haydn Society, familiarly known as H+H, is an American chorus and period instrument orchestra based in Boston, Massachusetts.
 Founded in 1815, it is the third oldest musical organization in the United States after the Stoughton Musical Society (founded in 1786) and the U.S. Marine Band (founded 1798), and the oldest continually performing arts organization in the United States.
Edward Faragher (1831–1908) was a Manx language poet, folklorist and cultural guardian.
 He is considered to be the last important native writer of Manx and perhaps the most important guardian of Manx culture during a time when it was most under threat.
 The folklorist, Charles Roeder, wrote that Faragher had "done great services to Manx folklore, and it is due to him that at this late period an immense amount of valuable Manx legends have been preserved, for which indeed the Isle of Man must ever be under gratitude to him."
 Faragher is also familiarly known in Manx as Ned Beg Hom Ruy.
The Carrier Sekani Tribal Council (familiarly known as CSTC) is a tribal council representing eight First Nations in the Central Interior of British Columbia.
 It was originally known as the "Lakes District Tribal Council".
 The CSTC was incorporated in 1979 and is a registered non-profit society.
Thessaloniki (Greek: Θεσσαλονίκη , "Thessaloníki", ] ), also familiarly known as Thessalonica or Salonica, is the second-largest city in Greece and the capital of Macedonia, the administrative region of Central Macedonia and the Decentralized Administration of Macedonia and Thrace.
 Its nickname is η Συμπρωτεύουσα ("Symprotévousa"), literally "the co-capital", a reference to its historical status as the Συμβασιλεύουσα ("Symvasilévousa") or "co-reigning" city of the Eastern Roman (Byzantine) Empire, alongside Constantinople.
The Society for Macedonian Studies was founded on April 29, 1939 in Thessaloniki, Greece.
 The purpose of the Society is the research on History and Folklore of Macedonia and the help for the development of the Intellectual development of Macedonian life.
The Philomathean Society of Phillips Academy is the second oldest secondary school debate union in the United States.
 Founded in 1825 the Philomathean Society, familiarly known as "Philo," meets weekly in the historical Debate Room of Bulfinch Hall.
 The earliest record of Philo's doings, preserved, bears the date January 5, 1825.