llOwnerSay(string message)
Says message to only the owner of the object running the script if the owner has been within the object’s simulator since logging into Second Life, regardless of where they may be in-world. Note: When the owner is not in the same sim this phenomenon only lasts a minute or two
This is useful for replacing llInstantMessage(llGetOwner(),msg) as there is no time penalty with llOwnerSay. This is also useful for replacing llWhisper(0,message) for instances where only the owner needs to be given the message (For example, “Dance Bracelet Initialized”).
Please use this function to reduce script spam by using it whenever the script needs to tell only the owner something (status info, interactive help text, etc). Other users tend to get annoyed with unnecessarily chatty scripts.
Remember, as with the other chat functions, message is truncated to 1023 bytes.
Example:
llOwnerSay("Hello, Avatar!");
Chat Output (visible only to object owner):
Hello, Avatar!
Q: What is the purpose for this additional chat command?
A: Many people have asked for a way to send private messages to the owner of an object without the delay penalty incurred by llInstantMessage. Many scripters will accomplish this using a llWhisper though it is not completely private, and may annoy people near the object. llOwnerSay is most useful for attachments where you want to get a lot of data back without spamming local chat with whisper or waiting for the instant messages to trickle in due to the time penalty they incur.
Q: How do I get it to work with someone who isn’t the owner?
A: You can’t. llOwnerSay is intended primarily for debug purposes or messages that only need the attention of the object owner. If you need to send a message to someone else, use llInstantMessage.
Q: How do I make llOwnerSay work without having been in the sim in which my object resides since logging into SL?
A: You can’t. You can either enter the sim once, or use llInstantMessage.
A: No, you need to be online and have been in the sim in which your llOwnerSay object is in since logging into SL. If you need to recieve messages when offline, use llInstantMessage.
A: No, llOwnerSay chat particles are only visible to the owner.
A: It silently fails, it does not halt the script.
Compare with llWhisper, llSay, llShout, llInstantMessage and llMessageLinked
Credit to: Lslwiki.net (not working) with changes made for brevity and clarity.