Should our 1D opening be alerted?
Rules on alerts are specified by the sponsoring organization, and may well be different for games played under different organization.
The ACBL alert chart does not specifically mandate an alert for a 1D bid wqhich promises an unbalanced hand, but does require an alert for &quot;Natural Calls Not Specifically Noted&quot; which show &quot;Unusual strength, shape, etc&quot;. The ACBL Alert procedure says:

The objective of the Alert system is for both pairs at the table to have equal access to all information contained in any auction. In order to meet this goal, it is necessary that all players understand and practice the principles of Full Disclosure and Active Ethics. Ethical bridge players will recognize the obligation to give complete explanations. They will accept the fact that any such information is entirely for the benefit of the opponents, and may not be used to assist their own partnership.
This procedure uses the admittedly &quot;fuzzy&quot; terminology of &quot;highly unusual and unexpected&quot; as the best practical solution to simplifying the Alert Procedure. &quot;Highly unusual and unexpected&quot; should be determined in light of historical usage rather than local geographical usage. To ensure full disclosure, however, at the end of the auction and before the opening lead declarers are encouraged to volunteer to explain the auction (including available inferences)

In light of that, I would be inclined to alert the 1D opening. Or I might ask a local director before the game if such a bid should be alerted. If in doubt it is always better to alert than not.
Note that one should never say more than &quot;alert&quot; until and unless an opponent asks for an alert to be explained. Offering an explanation unasked can itself be a violation.
In an informal game not sponsored by any organization, procedures are whatever the players agree on.