+=head1 CONSTANTS
+
+A number of constants have been provided for in the library.
+
+=over 4
+
+=item MEMCACHED_DEFAULT_PORT
+
+The default port used by memcached(3).
+
+=item MEMCACHED_MAX_KEY
+
+Default maximum size of a key (which includes the null pointer). Master keys
+have no limit, this only applies to keys used for storage.
+
+=item MEMCACHED_MAX_KEY
+
+Default size of key (which includes the null pointer).
+
+=item MEMCACHED_STRIDE
+
+This is the "stride" used in the consistent hash used between replicas.
+
+=item MEMCACHED_MAX_HOST_LENGTH
+
+Maximum allowed size of the hostname.
+
+=item MEMCACHED_VERSION_STRING
+
+String value of libmemcached version such as "1.23.4"
+
+=item MEMCACHED_MAJOR_VERSION
+
+Major version value. Such as 1.23.4, would be 1
+
+=item MEMCACHED_MINOR_VERSION
+
+Major version value. Such as 1.23.4, would be 23
+
+=item MEMCACHED_MICRO_VERSION
+
+Major version value. Such as 1.23.4, would be 4
+
+
+=back
+
+
+
+=head1 THREADS AND PROCESSES
+
+When using threads or forked processes it is important to keep an instance
+of C<memcached_st> per process or thread. Without creating your own locking
+structures you can not share a single C<memcached_st>. You can though call
+memcached_quit(3) on a C<memcached_st> and then use the resulting cloned
+structure.
+