Exploratory testing is a great way to uncover information about the product you are working on 
Part of exploratory testing is having charters to help guide the exploration.
On a previous project, I stored my charters at the bottom of the Jira stories. The reasoning was that a developer could pick that charter up with minimal effort if they were going to test a story. On another project, I was the only tester so a notebook was perfect for the job.
Where do you keep your charters and why?
I have only used charters in conjunction with Session Based Test Management and then they were part of the Session Reports. We did not use them to distribute testing work so there were at that stage no need to store charters somewhere else. I have tried to distribute work through charters but found that to be lacking. Instead I figured out that I can teach people how to create them with this “formula”.
[Action] [Subject] [Conditions] i.e. Analyze state handling of user session for new users.
Actions can be anything but here are some favorites.
Recon - figure out what it is all about to help find what charters you want to do.
Explore - when you just want to open ended test an area.
Analyze - when you want to dig deep into a specific thing.
Wrap Up - when you want to cover a the lose ends remaining like revisit areas and look at bug fixes
Take the - Take a specific tour
Finally I found mind maps to be the best documentation tool for most things exploratory since it is easy to follow different trains of though in a mind map.
Interesting, have you ever had difficulties with others when trying to follow mind maps?
Yes I have had problem with other following mind maps. In session based test management that is what the debriefing is for to make sure that we all follow the same formatting, terminology and if needed that the charter was sufficiently covered. For instance we use color coding to say this was “system information” this is a bug etc. and then you need to establish terms. Which the group commonly use in order to have freedom at the same time as you make it easier to share.
We manage exploratory tests in the same tool where we manage scripted test cases - in Practitest.
They have a structure type for Exploratory Tests and there is a special field for Charters and Guide points as well. They also have modules for different types of action items , only they call it Annotations.
One of the possible action items in the exploratory test structure is opening bugs, and we have bugs integrated with Jira - so the developers have access to Charters and guide points of the test as well.
I keep the charters in Gitlab in a personal repo. Everybody can access to this repo and read the charters. We can share the charters between dev and testers. The other reason is if my computer crashs I have a backup on Gitlab.
Stored somewhere people can find them. So in some teams that’s as docs in MS Teams/Sharepoint. For others in a cloud based mindmap tool. The less hassle to share and access the better. In my opinion