This specifies an extensible reader syntax for named value constructors. A reader prefix is followed by a tag (an identifier), and then expressions and literal text parameters. The tag can be though of as a class name, and the expression and literal text are arguments to an object constructor call. The reader translates &tag{...} to a list ($construct$:tag ...), where $construct$:tag is normally bound to a predefined macro.

This propsal depends on SRFI-109 (extended string quasi-literals) (in spite of having a lower number). It also shares quite of bit of syntax with SRFI-107 (XML reader syntax).