.. function:: memcached_return_t memcached_decrement_with_initial (memcached_st *ptr, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)
-.. function:: memcached_return_t memcached_increment_by_key (memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
+.. function:: memcached_return_t memcached_increment_by_key (memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
.. function:: memcached_return_t memcached_decrement_by_key (memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
.. function:: memcached_return_t memcached_decrement_with_initial_by_key (memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)
+ :param ptr: pointer to an initialized `memcached_st` struct
+ :param group_key: key namespace
+ :param group_key_length: length of the key namespace without any terminating zero
+ :param key: the key
+ :param key_length: length of the key without any terminating zero
+ :param offset: offset to increment/decrement
+ :param initial: initial value if `key` does not exist and `expiration` is not `MEMCACHED_EXPIRATION_NOT_ADD`
+ :param expiration: expiration as a unix timestamp or as relative expiration time in seconds
+ :param value: the resulting value after initialization/increment/decrement
+ :returns: `memcached_return_t` indicating success
DESCRIPTION
-----------