--- Get Item list ---
c ENUM_ITEMS\n
s 201 Items <count>\n
-s 202 Item <item_id> <price> <description>\n
+s >> Response to ITEM_INFO
...
s 200 List End\n
--- Get Item Information ---
c ITEM_INFO <item_id>\n
-s 202 Item <item_id> <price> <description>\n
-
+s 202 Item <item_id> <status> <price> <description>\n
+<status> "avail", "sold", or "error"
--- Get Users' Balances ---
c ENUM_USERS[ min_balance:<balance>][ max_balance:<balance>][ flags:<flagset>][ last_seen_before:<unix_timestamp>][ last_seen_after:<unix_timestamp>][ sort:<field>[-desc]]\n
s 201 Users <count>\n