Following the instructions in this IBM article, I have included a link to a record in an comm template. My link looks like this http://:HOSTNAME/maximo/ui/maximo.jsp?event=loadapp&value=:APP&uniqueid=:OWNERID.
This link from the IBM article only gets to the default, i.e "List" tab for most applications. Can I somehow add a specific tab (standard or custom) of named application when implementing this as a link in Comm Template?
Based on this blog post by Bruno Portaluri, and comments from others on that post, it looks like you should be able to add changetab=yourtabid to the URL.
Based on your question, the whole URL would then be http://:HOSTNAME/maximo/ui/maximo.jsp?event=loadapp&value=:APP&uniqueid=:OWNERID&changetab=plans if the app your link was to had a tab with ID plans, or XML <tab id="plans" ..., in it.