Memcache::add Add an item to the server &reftitle.description; boolMemcache::add stringkey mixedvar intflag intexpire Memcache::add stores variable var with key only if such key doesn't exist at the server yet. Also you can use memcache_add function. &reftitle.parameters; key The key that will be associated with the item. var The variable to store. Strings and integers are stored as is, other types are stored serialized. flag Use MEMCACHE_COMPRESSED to store the item compressed (uses zlib). expire Expiration time of the item. If it's equal to zero, the item will never expire. You can also use Unix timestamp or a number of seconds starting from current time, but in the latter case the number of seconds may not exceed 2592000 (30 days). &reftitle.returnvalues; &return.success; Returns &false; if such key already exist. For the rest Memcache::add behaves similarly to Memcache::set. &reftitle.examples; add('var_key', 'test variable', false, 30); ?> ]]> &reftitle.seealso; Memcache::set Memcache::replace