Hey, this is just my kind of thread
I feel many people here that own a lot of lights will use them on rotation rather than have assigned duties for each light. I do a bit of both, but lean more towards assignments.
First my main pocket (jeans/trousers) EDC rotation - I'll pick one when leaving the apartment. All of these can be considered to be "assigned" as my primary EDC light for general use:
Nitecore EC11: Nicer in the warmer months!
Nitecore EC21: Good all-rounder
Thrunite Archer 1A V2: Another good all-rounder but lower runtime.
Thrunite T10S: Sometimes carried in addition to another, but this one also has a specific assignment - with the cone it makes a nice flood light for power outage situations!
Now onto the specific assignments. Some of these are left around in easy locations for my wife to use.
Nitecore tube: Key chain light, also considered as my emergency (all other lights fail) EDC light. My wife also has one on her keyring.
Fenix E0: Hanging off the wall in the entrance for quick grabbing if the lights go out. I should attach a trit to it.
Panasonic 5mm LED (3xAA): Breaker cupboard. Another emergency grab light for power failures.
Fenix LD40: Bedside drawer. This mostly sits dormant, but it's our "SHTF" light if we get woken up by something bad. Always loaded with fully charged eneloops.
Thrunite TN12 (neutral white): In my backpack I take to work, doubles as my walking at night outside light.
Olight S10R: Night time indoor use, e.g. going to the bathroom without causing a disturbance.
Lights that used to have assignments but no longer do, and why - ofcourse more could fit into this category but these are the ones that stand out for me:
Fenix TK20: This was my walking outside at night light due to the tint and throw. It has been replaced by the TN12 now. The whining noise it makes on high power also makes it annoying to use indoors.
Surefire A2 (white LED): This was my work light. My old job involved lots of computer repair and dealing with cables, having a dual light source light was very convenient. Retired due to me moving away from CR123A batteries.
Inova T4: I used this for walking at night regularly many years ago. It was convenient but the PWM on low was annoying.
Fenix P1D: I used to carry it all the time when I first had it. Moved away from CR123A batteries.
Fenix E01: This was on my keyring for several years, and the finish was very beaten up but it still worked perfectly. I gave it to one of my brothers when I moved out as a kind of momento.
I have other lights that don't have assignments, which means they get used for all kinds of tasks (and sometimes EDC) or are not used much at the moment.