Technicals on Cover Letters?

I just want to know, quite generally, do people who have an idea about the technicals show that on their CV?

In London, interviews at both rounds are typically competency based; except the top 6 or so BB's and all of the boutiques....

I've got a knowledge of the technicals (enough to get me through Lazard technical application question, but not enough to get me through their first round interview)

For the rest of my applications, do I imply that I have a technical understanding, even though it's not huge, it shows i've done research etc etc; but if so, it would obviously be ridiculous to just giving formulas for the cost of equity etc (obviously i'd never do that, or hope no one would)

I.e. - it's difficult to incorporate; so, would you / do you leave it out and impress later on?