Unknown Sequence Type In MLST

Question

[utkarsh.sood]

Hello,

I am using MLST 1.8 (https://cge.cbs.dtu.dk/services/MLST/) for Sequence type determination. I am getting a four digit number as (e.g. ST_1195) result for one organism and unknown sequence type for another.

What is the significance of these results?

Thanks