har     par      cpg        va    flg next prev link hash hob   hal
 0005 %fef26078 0000dfb0 %04000000 007 0259 006e 0000 0000 fff0 0000 max=%1fff0000

Notes:

Flag bits 0x006 set signify a boundary sentinel record.

The boundary sentinel indicates the boundary between the shared and private arena address spaces. Consequently there is only one boundary sentinel to be found in a system.

hob is not relevant to sentinel records. (The value displayed originates from the max= field).

For OS/2 2.1, arena record 5 is boundary sentinel for the shared arena.

For a description of the fields formatted by .MA select .MA Output Field Descriptions