diff -r 4bbf32d81a21 -r 95e64220b38c src/pyams_viewlet/provider.py
--- a/src/pyams_viewlet/provider.py	Fri Jan 18 13:58:47 2019 +0100
+++ b/src/pyams_viewlet/provider.py	Fri Jan 18 15:24:45 2019 +0100
@@ -43,6 +43,9 @@
     static (like strings or integers), or can be variables defined into current template
     context; other Python expressions including computations or functions calls are actually
     not supported, but dotted syntax is supported to access inner attributes of variables.
+
+    Provider arguments can be passed by position but can also be passed by name, using classic
+    syntax as in ${structure:provider:my_provider(arg1, arg3=var3)}
     """
 
     def get_value(econtext, arg):