I have a PCB that requires a very specific selection of components such as ICs, diodes with specific electrical properties, etc (I won't go into too much detail).

With the BOM that is required for the PCBA service, if a column is inputted for aspecific PCB designator, how would component sourcing be done? Will we need to provide that and ship it in, or does JLC provide that at an additional cost?

More information regarding this would be amazing!