<<.preamble """What follows is a formal presentation of the syntax of the WikiText syntax for macro calls, using [[railroad diagrams|Railroad Diagrams]]. A [[simpler overview|Macro Calls in WikiText]] is also available.""">>
<$railroad text="""
"<<" name [: space [:{param-value}] ]">>"
"""/>
<<.place space>> denotes a sequence of [[whitespace characters|Filter Whitespace]].
The [[macro|Macros]]'s <<.place name>> is a sequence of non-whitespace characters other than `(` or `>`.
Each individual <<.place param-value>> has the following syntax:
<$railroad text="""
[: param-name [:space] ":" [:space] ] value [: space]
"""/>
The <<.place param-name>> is a sequence of letters (`A`--`Z`, `a`--`z`), digits (`0`--`9`), hyphens (`-`) and underscores (`_`).