registry.scheme.org/hash-syntax.scm

(id "#!")
(description "Identifier follows [R6RS+]; Unix script [SRFI 22]")

(id "#\"")
(description "Interpolated string [Gauche]")

(id "#(")
(description "Vector [R7RS]")

(id "#*")
(description "Incomplete string [Gauche]")

(id "#,")
(description "Reader constructor [SRFI 10]")

(id "#,")
(description "unsyntax [R6RS, syntax-case]")

(id "#,@")
(description "unsyntax-splicing [R6RS, syntax-case]")

(id "#/")
(description "Regular expression [Gauche]")

(id "#:")
(description "Keyword [Guile, Kawa, Racket]; Uninterned symbol [Gauche]")

(id "#;")
(description "S-expression comment [R6RS, R7RS, SRFI 62]")

(id "#<...>")
(description "Unreadable object [Gauche]")

(id "#<n>#")
(description "Datum reference [R7RS]")

(id "#<n>=")
(description "Datum label [R7RS]")

(id "#?")
(description "Debug macro [Gauche]")

(id "#[")
(description "Character set [Gauche]")

(id "#\\")
(description "Literal character [R7RS]")

(id "#`")
(description "quasisyntax [R6RS, syntax-case]; legacy string interpolation [Gauche]")

(id "#|")
(description "Block comment until |# [R6RS, R7RS, SRFI 30]")