BBP_PDHCF entries link to CRMD_ORDERADM_H missing in CRMD_LINK table

Hello friends,

Need help on the below topic:

I am building one report to bring data from table BBP_PDHCF with specific criteria for Custom fields , and to display the corresponding Object id and Object type value from table CRMD_ORDERADM_H .I am able to link these two tables using table CRMD_LINK 

BBP_PDHCF-SET_GUID = CRMD_LINK-GUID_SET

CRMD_LINK-GUID_HI  = CRMD_ORDERADM_H-GUID

Now coming to the issue, I have few entries in BBP_PDHCF table for which I don't find a linkage available in CRMD_LINK table.

What could be reason for this? Can it be due to some specific status of the document /or some specific reason if you can suggesr would be relally helpful.Thanks a lot in advance.