Order of Precedence for Custom Properties in vCAC

 When the same property exists in more than one source, a specific order is followed when applying properties to the machine.

You can add custom properties that apply to provisioned machines to the following elements:

■	A reservation, to apply the custom properties to all machines provisioned from that reservation
■	A business group, to apply the custom properties to all machines provisioned by business group members
■	A global or local blueprint, to apply the custom properties to all machines provisioned from the blueprint
■	Build profiles, which can be incorporated into any global or local blueprint, to apply the custom properties to all machines provisioned from the blueprint
■	A machine request, if you are a business group manager, to apply the custom properties to the machine being provisioned
■	The applicable approval policy, if any exist and if advanced approval support is enabled, to require approvers to provide the values to be applied to the machine being approved

The full order of precedence for custom properties is that any property value specified in a source later in the list overrides values for the same property specified in sources earlier in the list. The order is shown in the following list:

1	Build profile
2	Blueprint
3	Business group
4	Compute resource
5	Reservations
6	Endpoint
7	Runtime

For vApps, the order is similar, as shown in the following list:

1	Build profile, specified on a vApp component blueprint
2	vApp component blueprint
3	Build profile, specified on a vApp blueprint
4	vApp blueprint
5	Business group
6	Compute resources
7	Reservations
8	Endpoint
9	Runtime specified on a vApp
10	Runtime specified on a component machine

Any runtime property takes higher precedence and overrides a property from any source. A custom property is marked as runtime if the following conditions exist:

■	The property is marked as Prompt User, which specifies that the user must supply a value for it when requesting a machine. This requires that the machine requestor customize individual characteristics of each machine, or gives them the option of doing so when a default value is provided for the required property.
■	A business group manager is requesting a machine and the property appears in the custom properties list on the Properties tab of the Confirm Machine Request page.

Custom properties in reservations and business groups may be applied to many machines so they should be used carefully. Their use is typically limited to purposes related to their sources, such as resource management, line of business accounting, and so on. Specifying the characteristics of the machine to be provisioned is generally done by adding properties to blueprints and build profiles.

Each blueprint of any type can optionally incorporate one or more build profiles and thereby inherit the custom properties in those profiles. Build profiles are especially useful for applying common sets of properties for specific purposes to a wide range of blueprints. For example, your site might want to add a second disk to, customize Microsoft Remote Desktop Protocol behavior for, and enable Active Directory cleanup for a wide variety of machines. If a build profile with the necessary properties is created, it can be incorporated into all of your blueprints, local or global.

When creating and managing build profiles, a fabric administrator can load a number of predefined property sets to add several related properties all at once, instead of one by one.

Source:-
VMware Documentation