After experimenting around with /script.
Type anything in combat/chat log, this can also be used as a scam.
(Notice : only you can see it)
Im working on changing color.
1.
CHAT LOG
Code:
/script ChatFrame1:AddMessage("\124cffffff00\124Hachievement:1234:0000000000000001:1:12:31:8:4294967295:4294967295:4294967295:4294967295\124hWRITE MESSAGE HERE\124h\124r")
Replace a text were WRITE A MESSAGE HERE is. Yellow text
2.
COMBAT LOG
Code:
[IMG]file:///C:/DOCUME%7E1/Nils/LOKALA%7E1/Temp/moz-screenshot-1.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/Nils/LOKALA%7E1/Temp/moz-screenshot-2.jpg[/IMG]/script ChatFrame2:AddMessage("\124cffffff00\124Hachievement:1234:0000000000000001:1:12:31:8:4294967295:4294967295:4294967295:4294967295\124hOpirity dies of hunger.\124h\124r")
Change "OPIRITY DIES OF HUNGER." to something else. Yellow text.

NOTICE BEFORE U START FLAMIN'
This can maybe be used by private servers to look real. Good scam.