I used to put the name of those serving on the JC, the name of the chairman, the name of the disfellowshipped person, the date of the committee and the date of the announcement to the congregation -- I would also add -- not appealed or appealed as the case may be.
If it was sexual I used to put porneia/fornication or adultery. I never put any detail - -for example I would NOT put "he put his hand inside her blouse and felt her breast and manipulated her nipples" --- I will not put any other examples of what I did NOT write -- do not want to get a serious thread deleted.
I personally used to keep old records also -- did not destroy them -- until very close to resigning as an elder when I had a great big burning session and dispatched old notes to the fire!