some inconsistencies in the item section at https://www.zabbix.com/documentation/2.4/manual/config/items/itemtypes/zabbix_agent
a) empty parameters sometimes are denoted with an empty cell, sometimes with a single dash "-"
b) "Return value" sometimes is just a description like "Integer", but sometimes a full sentence like "Returns '1' if agent is available, nothing if unavailable." - probably should be changed to "'1' if agent is available, nothing if unavailable."
all item type pages should be reviewed for all versions