The print edition of the Duden (24 ed 2006) does not list any of these abbreviations. Therefore, if you use them in a (formal) document it may be appropriate to explain them in a list of abbreviations.
For abbrevations in general Duden writes:
Bei Abkürzungen, die nur in geschriebenen Texten verwendet werden, wir meist keine Beugungsendung gezeigt.
Abbreviations are usually written without showing the conjugation ending.
However there are exceptions of this rule than may be applied to avoid missunderstandings:
- If the abbreviation ends with the last letter of the abbreviated word we may add the ending at the end of the abbreviation:
die Bde. = die Bände
- For abbreviated names the ending is set after the abbreviating dot:
B.s. Werke = Brechts Werke
- Sometimes plural forms are built by doubling of letters:
Jgg. = Jahrgänge
Even though the 24th edition of Duden does not list the abbreviation for jemand they do use them occasionally in this edition in the form of