# text.div
This code system http://hl7.org/fhir/permission-rule-combining defines the following codes:

Code | Display | Definition
deny-overrides | Deny-overrides | The deny overrides combining algorithm is intended for those cases where a deny decision should have priority over a permit decision.
permit-overrides | Permit-overrides | The permit overrides combining algorithm is intended for those cases where a permit decision should have priority over a deny decision.
ordered-deny-overrides | Ordered-deny-overrides | The behavior of this algorithm is identical to that of the “Deny-overrides” rule-combining algorithm with one exception. The order in which the collection of rules is evaluated SHALL match the order as listed in the permission.
ordered-permit-overrides | Ordered-permit-overrides | The behavior of this algorithm is identical to that of the “Permit-overrides” rule-combining algorithm with one exception. The order in which the collection of rules is evaluated SHALL match the order as listed in the permission.
deny-unless-permit | Deny-unless-permit | The “Deny-unless-permit” combining algorithm is intended for those cases where a permit decision should have priority over a deny decision, and an “Indeterminate” or “NotApplicable” must never be the result. It is particularly useful at the top level in a policy structure to ensure that a PDP will always return a definite “Permit” or “Deny” result.
permit-unless-deny | Permit-unless-deny | The “Permit-unless-deny” combining algorithm is intended for those cases where a deny decision should have priority over a permit decision, and an “Indeterminate” or “NotApplicable” must never be the result. It is particularly useful at the top level in a policy structure to ensure that a PDP will always return a definite “Permit” or “Deny” result. This algorithm has the following behavior.

# concept[].definition
The deny overrides combining algorithm is intended for those cases where a deny decision should have priority over a permit decision.

# concept[].definition
The permit overrides combining algorithm is intended for those cases where a permit decision should have priority over a deny decision.

# concept[].definition
The behavior of this algorithm is identical to that of the “Deny-overrides” rule-combining algorithm with one exception.  The order in which the collection of rules is evaluated SHALL match the order as listed in the permission.

# concept[].definition
The behavior of this algorithm is identical to that of the “Permit-overrides” rule-combining algorithm with one exception.  The order in which the collection of rules is evaluated SHALL match the order as listed in the permission.

# concept[].definition
The “Deny-unless-permit” combining algorithm is intended for those cases where a permit decision should have priority over a deny decision, and an “Indeterminate” or “NotApplicable” must never be the result. It is particularly useful at the top level in a policy structure to ensure that a PDP will always return a definite “Permit” or “Deny” result.

# concept[].definition
The “Permit-unless-deny” combining algorithm is intended for those cases where a deny decision should have priority over a permit decision, and an “Indeterminate” or “NotApplicable” must never be the result. It is particularly useful at the top level in a policy structure to ensure that a PDP will always return a definite “Permit” or “Deny” result. This algorithm has the following behavior.