-each repeat variable is substituted; the second time, the second value
-for each repeat variable is substituted; and so on.
-
-Repeat variable substitutions work like macros. They take place
-anywhere in a line that the repeat variable name occurs as a token,
-including command and subcommand names. For this reason it is not a
-good idea to select words commonly used in command and subcommand names
-as repeat variable identifiers.
-
-If PRINT is specified on @cmd{END REPEAT}, the commands after substitutions
+each dummy variable is substituted; the second time, the second value
+for each dummy variable is substituted; and so on.
+
+Dummy variable substitutions work like macros. They take place
+anywhere in a line that the dummy variable name occurs. This includes
+command and subcommand names, so command and subcommand names that
+appear in the code block should not be used as dummy variable
+identifiers. Dummy variable substitutions do not occur inside quoted
+strings, comments, unquoted strings (such as the text on the
+@cmd{TITLE} or @cmd{DOCUMENT} command), or inside @cmd{BEGIN
+DATA}@dots{}@cmd{END DATA}.
+
+Substitution occurs only on whole words, so that, for example, a dummy
+variable PRINT would not be substituted into the word PRINTOUT.
+
+New variable names used as replacements are not automatically created
+as variables, but only if used in the code block in a context that
+would create them, e.g.@: on a @cmd{NUMERIC} or @cmd{STRING} command
+or on the left side of a @cmd{COMPUTE} assignment.
+
+Any command may appear within @subcmd{DO REPEAT}, including nested @subcmd{DO REPEAT}
+commands. If @cmd{INCLUDE} or @cmd{INSERT} appears within @subcmd{DO REPEAT},
+the substitutions do not apply to the included file.
+
+If @subcmd{PRINT} is specified on @cmd{END REPEAT}, the commands after substitutions