Debian release of PCRE 4.5 had
 
 PCRE_LIB_VERSION=13:0:10
 PCRE_POSIXLIB_VERSION=13:0:10
 
 which corresponds to latest debian-revision (soname libpcre.so.3,
 installed as libpcre.so.3.9.0) and followed the instructions about version
 numbering in the libtool manual:
 |  3. If the library source code has changed at all since the last
 |     update, then increment REVISION (`C:R:A' becomes `C:r+1:A').
 
 13:1:10
 
   4. If any interfaces have been added, removed, or changed since the
      last update, increment CURRENT, and set REVISION to 0.
 
 14:0:10
 
   5. If any interfaces have been added since the last public release,
      then increment AGE.
 
 14:0:11
 
   6. If any interfaces have been removed since the last public release,
      then set AGE to 0.
 
 n/a
 
 Therefore I'm using 14:0:11 for this release of PCRE 5.0

--- pcre-6.3.orig/configure.in
+++ pcre-6.3/configure.in
@@ -38,8 +38,8 @@
 dnl Provide versioning information for libtool shared libraries that
 dnl are built by default on Unix systems.
 
-PCRE_LIB_VERSION=0:1:0
-PCRE_POSIXLIB_VERSION=0:0:0
+PCRE_LIB_VERSION=15:0:12
+PCRE_POSIXLIB_VERSION=15:0:12
 PCRE_CPPLIB_VERSION=0:0:0
 
 dnl Handle --disable-cpp
--- pcre-6.3.orig/configure
+++ pcre-6.3/configure
@@ -1514,8 +1514,8 @@
 POSIX_MALLOC_THRESHOLD=-DPOSIX_MALLOC_THRESHOLD=10
 
 
-PCRE_LIB_VERSION=0:1:0
-PCRE_POSIXLIB_VERSION=0:0:0
+PCRE_LIB_VERSION=15:0:12
+PCRE_POSIXLIB_VERSION=15:0:12
 PCRE_CPPLIB_VERSION=0:0:0
 
 
--- pcre-6.3.orig/pcreposix.h
+++ pcre-6.3/pcreposix.h
@@ -109,10 +109,15 @@
 
 /* The functions */
 
-extern int regcomp(regex_t *, const char *, int);
-extern int regexec(const regex_t *, const char *, size_t, regmatch_t *, int);
-extern size_t regerror(int, const regex_t *, char *, size_t);
-extern void regfree(regex_t *);
+extern int pcreposix_regcomp(regex_t *, const char *, int);
+extern int pcreposix_regexec(const regex_t *, const char *, size_t, regmatch_t *, int);
+extern size_t pcreposix_regerror(int, const regex_t *, char *, size_t);
+extern void pcreposix_regfree(regex_t *);
+
+#define regcomp pcreposix_regcomp
+#define regexec pcreposix_regexec
+#define regerror pcreposix_regerror
+#define regfree pcreposix_regfree
 
 #ifdef __cplusplus
 }   /* extern "C" */