Is there any reason why this conditional wouldn’t work? I can only get the affirmative portion to work (Do A). The conditional does not work for entries that are not category 15 or 17 (Do B).
{exp:channel:entries limit="1" channel="items_of_interest" status="open|hidden"}
{categories}
{if category_id == "15" OR category_id == "17"}
Do A
{if:else}
Do B
{/if}
{/categories}
{/exp:channel:entries}