- "Name of the identifier referring to the current expression.
-The default value is `exp'. You can use this name in the search
-prompt to refer to the value of the currently tested expression."
+ "Identifier referring to the current expression in pattern input.
+When entering a PATTERN in an interactive \"el-search\" command,
+the pattern actually used will be
+
+ `(and ,el-search-this-expression-identifier ,pattern)
+
+The default value is `exp'."