Low Mass with Four Servers

[@manwithblackhat]

I had always understood that only a bishop could have more than two servers for a (Pontifical) Low Mass. Are there any special circumstances that would apply to a priest, in order to have four servers for a Low Mass?

[@manwithblackhat]

And by the way, thank you for the magnificent improvements in progress to the Sancta Missa website. I look forward to its completion.