WellSpyder, on 2017-March-09, 03:23, said:
I don't think it is practical to go into more detail about what "top of sequence" means to you when first asked about leads. But I must admit I wouldn't be very happy with this explanation, because I have no idea what "invitational" leads are.
Fair enough.
Here (I believe) "invitational" is a common term for a small card led from a suit which the leader hopes to establish with his partner's help.
Bringing us back to my earlier question: What is meant by "standard" in OP? I have no idea what that is supposed to be.