This is from CIC document IP8:
(Section 5: Procedures)
F. ADMINISTRATIVE DEFERRAL OF REMOVAL
The Canada Border Services Agency has agreed to grant a temporary administrative deferral of removal to applicants who qualify under this public policy. The deferral will not be granted to applicants who:
• Are inadmissible for security (A34), human or international rights violations (A35), serious criminality and criminality (A36), or organized criminality (A37);
• Are excluded by the Refugee Protection Division under Article F of the Geneva Convention;
• Have charges pending or in those cases where charges have been laid but dropped by the Crown, if these charges were dropped to effect a removal order;
• Have already benefited from an administrative deferral of removal emanating from an H&C spousal application;
• Have a warrant outstanding for removal;
• Have previously hindered or delayed removal; and
• Have been previously deported from Canada and have not obtained permission to return.
And, from Appendix A: Case Type List for Application of the Public Policy
[Pending HC2 application]-
If it initially appears that the applicant meets the requirements of the Spouse or Common-law Partner in Canada class, but it is later determined that the applicant is ineligible for the class (e.g. invalid sponsorship), reassess the application under general IP5 provisions. This is because the applicant originally applied for H&C consideration. However, because these applicants do not meet the requirements of this public policy, they are required to demonstrate unusual and undeserved or disproportionate hardship to the H&C decision-maker. (HC1)