Poland
Practice Relating to Rule 115. Disposal of the Dead
Section D. Burial in individual or collective graves
Poland’s Procedures Governing the Interment of Soldiers Killed in Action (2009) states: “Whenever possible, the bodies of soldiers belonging to the national armed forces, allied forces or enemy forces, as well as the bodies of non-combatants, shall be buried in individual graves.”
The Procedures also states: “The graves may be dug as individual, group or trench graves.”
The Procedures further states in the section on definitions:
Group burial
Burial in a common grave of two or more unidentified bodies or human remains.
…
Trench burial
The burial of bodies in collective graves, in the event of very heavy casualties, when the bodies or remains cannot be separated from one another, and cannot be identified.
The Procedures also states: “Civilian members of the armed forces who had not participated in hostilities shall be buried in line with procedures established for the burial of the bodies of soldiers.”