If you see a guy left accurate feedback on others, Include them on your trust list. That's how it should work.
Is it a mandatory condition that I have to look at their trust feedback on others, before including them into my trust list?
Read this again:
Follow the link to read the full description. This forum is all about freedom, but if you follow what it says there, you could call it mandatory. I believe it's necessary for the Trust system to work properly.
I don't think you can call it mandatory. Maybe it should be, but clearly it isn't. Everyone has the freedom to include who they want in their trust list, in the the way they want, for they reasons they want, regardless of suggested guidelines. It simply means that not all DT1 eligible members should be DT1 if they aren't creating their trust lists appropriately and in the way they
should be (based on a users judgement).
If there was a confirmation page after trust list edits stating "Are you sure you trust/distrust these users judgement?", then sure we could call it compulsory. But for now that's not how it works. Maybe some users simply want to only see the trust feedback from users they trust, regardless of whether their judgement is correct or not. This is worth taking into consideration I think and possibly why tranthidung had the list they did.
It just means if that's the case then users should either submit to being blacklisted, or otherwise excluded as a DT1 member, as has been the case here. Now tranthidung is able to see trust feedback from users they trust, as they desire, without any further controversy about it. After all there is no direct option from users to be included in DT1 or not, so there is no formal agreement to this as it were.