How were derringer "hideout" guns carried?

[Naphtali]

Single barrel single shot cap lock derringers - a Philadelphia "John W. Booth" type of hideout gun - seems to be intended for concealed carry in a coat pocket or vest pocket, et al. If carried concealed and capped, how did carrier make sure the cap stayed where it belonged? And how did carrier secure the hammer so it didn't jar itself into firing?

It seems to me to be beyond silly to carry a hideout gun uncapped, kind've defeating its purpose.

[Muley Gil]

They were carried on "half cock", a position on the tumbler that kept the hammer off of the percussion cap/nipple, but not fully cocked. A half cock notch should be deep enough that a strong pull on the trigger won't release it. The hammer is drawn back to full cock to fire.