I will determine the proper time to give them the belt and give them the belt personally. If I taught them and consider me their instructor, it makes no sense for anybody else to promote them at a seminar when they don't know their training history or were present to monitor their progress. The only certificate they need (to answer somebody else's question) is their knowledge and ability on the mat. Only truth exists on the mat.
Since we have a number of upper belts, I take into strong consideration the opinions of my friends and training partners regarding promotions. We see eye to eye on these matters. The decision to promote would be mine, but they would sign off if needed on any IBJJF requirements since every belt will need a card soon and would offer their blessing on my decisions.
I feel that those that might not know me would argue that I am watering down the sport. That somehow because I don't provide a certification with my stripes and belt waters down the process - despite the fact that a huge number of legit gyms dont. Ironically, I feel that promotion standards at the places being loud about standards are often the ones who promote on standards that I dont agree with.
If your interested more in my point of view, I wrote 13 reasons to join my gym on our website. Reason 11 deals with promotion standards.
13 reasons to join Brea Jiu-Jitsu
I wanted to address Mcbains comment, but I decided to leave it at a no comment. Suffice to say, I have my instructors blessing and thats all that is needed on an internet forum.