Overview
Policy precedence was explained In a previous Wiki article,
Domino Policy Precedence Explained. But one aspect of Domino Policies was not covered, namely the How To Apply (HTA) feature. Whereas policy precedence determines how the settings from several policies are combined, the How To Apply feature controls how settings from the same policy (or effective policy) are controlled over time.
Where they can be used
The How To Apply feature was added in 8.0, but it does not exist for all policy setting types. It is only currently used by Desktop, Mail, Activities, Traveler, and Symphony settings. It is not used for Archiving, Registration, Roaming, Security, and Setup. The latter group will for the most part only have the "Don't set value" checkbox.
The four options
As can be seen from the image below there are four options that can be chosen on a per field basis:
Don't set value - This does NOT mean to use a default value for the setting, instead this means to treat the setting as if it does not exist at all. This setting is particularly useful in those situations where you don't want values in one policy masking those in a policy with lower precedence. For example, you want to set some specific settings in a dynamic policy but have the rest come from an organizational policy. Due to precedence, the value in the dynamic policy would take precedence even if it was empty! So in that case you would want to set "Don't set value" for the majority of the settings and then have another setting like "Set value and prevent change" for those values you really want to set.
Set initial value - This means to set the value the first time the policy is applied. After that, the end user can make whatever changes the want. This prevents the users settings from being changed every time the policy is changed. This setting is good for those cases where the setting is not a critical one (i.e. is specified by company policy) and it doesn't matter if the end user changes the value. Another way of looking at is that from an administrator's point of view, the frequency of change of the value is no concern of theirs.
Set value whenever modified - This means that the value will be set whenever the policy is modified, thus overwriting the users customization. However, after the new setting is applied, the user can still change the value.
Set value and prevent changes - This means that the setting is locked down. Namely, the value will be set initially and whenever the policy is changed and the user cannot make any changes to the value.
It is important to note that the
Inherit and
Enforce settings for a setting also apply to its HTA setting. So if a field's HTA is set to "Don't set value" and the Enforce checkbox is enabled, no value will exist for that setting in the effective policy.
Setting HTA values for every field
There might be cases where you want to set all of the fields to have a particular HTA setting. Doing that for every field would be very cumbersome. So for those settings that have HTA settings, there is an action at the top of the form that allows you to do this:
So for an example, in an explicit policy setting document one might use the "Don't set value for all fields" option to prevent empty field values from masking an organization or dynamic policy setting. Then only a small number of settings could be changed to "Set initial value". In this way, the explicit policy can be more easily used in combination with other policies instead of creating sets of explicit policies that have every setting set with only a few differences.
Difference between Precedence and HTA revisited
As mentioned in the beginning of this article, precedence and HTA have different areas of responsibility when it comes to policies. Precedence determines what settings get set and their values. HTA determines the persistence of those settings over time. So where precedence might say that the Required Change Interval for passwords is 90 days and that the Low Battery Threshold warning is 20%, HTA allows an administrator to configure a policy that says that an end user can't the former but can change the latter. Therefore, HTA tends to have much more of an impact on the end user experience. For example, an administrator might want to enforce company policies by using the
Set value and prevent changes option for security settings. But that could be overkill for a setting like Icon Color Scheme, where the
Set initial value option might make more sense. Using the
Set initial value option also prevents end user settings from getting 'slammed' every time an administrator makes a change to a policy. As can be seen then, HTA settings require a balance between administrator and end user control.
Conclusion
Whereas precedence controls WHAT the value of a setting is the How To Apply feature clearly controls HOW that setting can be changed. Together these two aspects of policies allows for great administrative control over the settings in a Domino domain. Understanding the focus of each of these two features will allow the administrator to craft policies that make their jobs easier and keep the end users happy!