I am not sure how to alphabetize things like St. or Mc Donald, do you spell out Saint or drop the space between c and D? Not sure what to do?

Have a good look at the White Pages of the
Telephone Directory.
You will find all the examples there.

Thank you ROLCAM for the answer, how stupid of me, I never thought of the phone book.
Thank you again for your help, Ruth

How is this alphabetized? If there is a period and space, is it a separate unit? If there is no space between the period, is it the same? Totally confused.
J. F. Mfg.
J.F.W. Works
J.J. Mailing
JJG King