On my way in to shul, I was stopped by the rabbi. He told me that so-and-so was unavoidably detained and would not be able to say kaddish for his father-in-law. He gave me the deceased's name and asked me to "have him in mind." I said "yes" reflexively and went in to shul.
There are many situations where we talk about having someone or something in mind. Someone else makes a bracha and "has me in mind" and I have in mind to be yotzei. I make a bracha on one thing but have something else "in mind" as well. We can learn "for" someone and have that person in mind.
But how exactly do we do that? When I was saying kaddish, was I supposed to think of the name I was given while saying the words? For every kaddish? For the duration of the kaddish or just at certain points? I don't usually think of my father's name while I am saying kaddish so am I doing something wrong?
The same holds for other cases of "having in mind" - do I have to be thinking actively and "linguistically" [I am aware that he is saying the bracha and I intend for him to help me fulfill my obligation] or do I just listen with awareness and that's enough? Do I have to time my declaration or maintain it in mind the entire time?