diff --git a/runtime/doc/if_cscop.txt b/runtime/doc/if_cscop.txt
index 91dd4c6..f3f1a49 100644
--- a/runtime/doc/if_cscop.txt
+++ b/runtime/doc/if_cscop.txt
@@ -271,6 +271,15 @@
 	:set cst
 	:set nocst
 <
+							*cscoperelative* *csre*
+If 'cscoperelative' set, then in absence of a prefix given to cscope (prefx
+is the argument to -P option of cscope), basename of cscope.out location
+(usually the project root directory) will be used as the prefix to construt
+absolute path.The default is off. Note: This option is only effective when
+cscope (cscopeprg) is initialized without a prefix path (-P). Examples: >
+	:set csre
+	:set nocsre
+<
 							*cscopetagorder* *csto*
 The value of 'csto' determines the order in which |:cstag| performs a search.
 If 'csto' is set to zero, cscope database(s) are searched first, followed
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index a5f6148..5759760 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -2209,6 +2209,16 @@
 	Specifies whether to use quickfix window to show cscope results.
 	See |cscopequickfix|.
 
+						*'cscoperelative'* *'csre'*
+'cscoperelative' 'csre' boolean (default off)
+			global
+			{not available when compiled without the |+cscope|
+			feature}
+			{not in Vi}
+	In the absence of a prefix (-P) for cscope. setting this option enables
+	to use the basename of cscope.out path as the prefix.
+	See |cscoperelative|.
+
 				*'cscopetag'* *'cst'* *'nocscopetag'* *'nocst'*
 'cscopetag' 'cst'	boolean (default off)
 			global