Cháng Táng 常棠 (fl. early thirteenth century), zì Shàozhòng 召仲, hào Zhúchuāng 竹忩, native of Hǎiyánxiàn 海鹽縣 in Jiāxīngfǔ 嘉興府 (modern northern Zhèjiāng on the south shore of Hángzhōu Bay). His official career is undocumented; the Sìkù tíyào explicitly states “shìlǚ wèixiáng 仕履未詳” — likely a local jūshì literatus rather than an officeholder. He is known solely as the author of the Hǎiyán Gǎnshuǐ zhì 海鹽澉水志 KR2k0019, the earliest extant Chinese zhènzhì (garrison-town gazetteer), in 8 juan, completed in Shàodìng 3 (1230) at the request of Luó Shūsháo 羅叔韶, then jiān Gǎnpǔzhèn shuì (supervisor of taxes at the Gǎnpǔ garrison-town in Hǎiyán). CBDB id 13504 has him as a unique entry without lifedates or further biographical information; the Sìkù and standard reference works concur on the lack of detail.