The strange behavior of player if NPC can be see but not allowed in default range 100 for dialogue.
The retail behavior of Fairy Mimyu vs standart L2J in quest for strider.
This is retail implementation for getting L2OFF data for site w/o direct connections to database, etc. NC Soft uses it for all gameservers. You can try to check it. If you want to use it for L2J server then you need implement responce for ProtocolVersion -3 in gameserver code. Many times ago i’m used it for getting info from L2OFF servers and for own project site. As example L2ON.NET still uses it.
Implementation of temporary item’s system from higher chronicles for Interlude servers. One difference with retail system, is not displayed the remaining time for temporary item. Interlude client have many limitations for this. But it can be solved using unique HTML page with showing all temporary items for character — location and remaining time.