Find the opcode that parcours an item list (such as inventory)

[Paul44]

Title is a bit generic, but basically like to tackle/learn 2 things here:
a. the/a game allows the gamer to view an inventory/collectibles/etc list: how would one approach his/her reseach to find the opcode that handles "browsing this list"... which should allow one to get the proper struct(s) of these items ?
Note: some list - such as a buy/sell list - come with values, making things usually easier to find; i'm more interested in "plain" lists here.
b. what is a/the approach to also find the descriptive(s) used in that list (in case of multi_lang games)?
These descriptives - in general - are loaded temporarily, and mem_locations change on the fly. Iow one needs to find the function that loads the descriptive per item, and understand what is passed on to that function ?!

eg: you can find photos (~ collectibles) ingame, which can be viewed, when found. their title_descriptives in the list differ per language. Goals:
1. find the (possible) flag to get all/missing enabled
2. show the list to the gamer with appropriate descriptives