Do not use <e> or [d] or anything like that infront of your text. Just speak English (that is, ICly, "Common").

The odd actual word of non-common where it's painfully obvious to everyone what you're saying e.g. Elves referring to certain other Elves as Tel'Quessir, some people referring to certain Halflings as Hin, and so forth, is acceptable. Whole sentences written in actual non-common text is not.

If your intention is to exclude other players from what you're saying, there is a much simpler prefix to use. /w. That is, whisper.