@samp{auto} is represented using @code{#:auto}.
@item PARAM_UINTEGER
-The value is an unsigned integer. The value of 0 should be
-interpreted to mean ``unlimited''.
+The value is an unsigned integer. The value of @code{#:unlimited}
+should be interpreted to mean ``unlimited'', and the value of @samp{0}
+is reserved and should not be used.
@item PARAM_ZINTEGER
The value is an integer.
The value is an unsigned integer.
@item PARAM_ZUINTEGER_UNLIMITED
-The value is an integer in the range @samp{[0, INT_MAX]}.
-A value of @samp{-1} means ``unlimited'', and other negative
-numbers are not allowed.
+The value is an integer in the range @samp{[0, INT_MAX]}. The value
+of @code{#:unlimited} means ``unlimited'', the value of @samp{-1} is
+reserved and should not be used, and other negative numbers are not
+allowed.
@item PARAM_STRING
The value is a string. When the user modifies the string, any escape