This site is a static rendering of the Trac instance that was used by R7RS-WG1 for its work on R7RS-small (PDF), which was ratified in 2013. For more information, see Home.
Source for wiki VerticalLineSymbols version 2
Update for Scheme 9
Racket, Gauche, MIT, Gambit, Chicken, Bigloo, Kawa, SISC, Chibi, Chez, !Ikarus/Vicare, STklos, KSi, Rep, Oaklisp, Owl Lisp all understand `|...|` syntax.
Scsh, Guile, SCM, NexJ, Shoe, !TinyScheme, Dream, Scheme 7, BDC, Elk, UMB, VX treat `|` as an ordinary
Scheme48, Larceny, Ypsilon, Mosh, !SigScheme, RScheme, XLisp, Schemik, Scheme 9 all report syntax errors.
!IronScheme gets hung up reading characters from the input.