This has been well covered recently in this forum, almost to the point of becoming annoying.  Please take note and pass the word to your ham friends. 
1)  FCC RULES PART 97 DOES NOT REQUIRE OR EVEN MENTION THE IDEA OF MODIFYING YOUR ISSUED OPERATOR CALL SIGN WITH A /P, /M, OR /R SUFFIX.  It has been over 45 years since that ID method and the single licensed station location concept was abandoned by the FCC,
2)  Well meaning amateur "Elmers", PLEASE STOP teaching new hams those archaic cancelled ID rules which do not exist in Part 97. They are incompatible with the advanced digital QSO technologies available to us.  The ITU defines a reversed format for amateur DX operation outside the licensee's country which uses the host country's assigned prefix. 
3)  When operating WSJTx modes you enter your issued callsign (maximum 6 characters) and your grid square. Nothing else will fit into the highly compressed data protocols of these weak signal modes and be readable by your QSO partner at the other end.  Meanwhile, ARRL and others offering virtual QSL services have added multiple location capability into their packages, specifically to accomodate amateur operators with more than one station equipment location. 
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Karl  WA8NVW  OH
WA8NVW@...
in WSJTX@groups.io

Karl,

modes like FT8, FT4, MSK144, Q65, and FST4, which all share the same basic source encoding rules, have a great deal of flexibility for nonstandard callsigns (by non-standard I mean in terms of these modes definition of a standard callsign which is more complex than "maximum of 6 characters"). If a nonstandard callsign is used with these modes then there are restrictions on what other information can be passed in standard format messages. The main restriction is that gridsquares cannot be conveyed in CQ or QRZ messages, another secondary but important restriction is that two stations with such nonstandard callsigns cannot easily work each other, yet another is that the special contest modes do not support nonstandard callsigns.

73
Bill
G4WJS.