diff --git a/basis/compiler/tree/tree-docs.factor b/basis/compiler/tree/tree-docs.factor
index 7c8d89473f..7b6e254fd7 100644
--- a/basis/compiler/tree/tree-docs.factor
+++ b/basis/compiler/tree/tree-docs.factor
@@ -1,7 +1,10 @@
 USING: assocs help.markup help.syntax kernel sequences stack-checker.alien
-stack-checker.visitor ;
+stack-checker.visitor words ;
 IN: compiler.tree
 
+HELP: node
+{ $class-description "Base class for all SSA tree nodes." } ;
+
 HELP: #alien-node
 { $class-description "Base class for alien nodes. Its " { $snippet "params" } " slot holds an instance of the " { $link alien-node-params } " class." } ;
 
@@ -9,7 +12,14 @@ HELP: #alien-invoke
 { $class-description "SSA tree node that calls a function in a dynamically linked library." } ;
 
 HELP: #call
-{ $class-description "SSA tree node that calls a word." } ;
+{ $class-description "SSA tree node that calls a word. It has the following slots:"
+  { $table
+    { { $slot "word" } { "The " { $link word } " to call." } }
+    { { $slot "in-d" } { "Sequence of input variables to the call. The items are ordered from top to bottom of the stack." } }
+    { { $slot "out-d" } { "Output values of the call." } }
+    { { $slot "info" } { "An assoc that contains various annotations for the words input and output values. It is set during the propagation pass of the optimizer." } }
+  }
+} ;
 
 HELP: #introduce
 { $class-description "SSA tree node that puts an input value from the \"outside\" on the stack." } ;