Adjourned for mention means only that, on the adjourned date, the case will be mentioned before the Court. It will not be heard, it won't be given more than a few minutes and there is no need for any witnesses to attend.
It generally means that there are ongoing matters which need to be resolved between the parties before (a) it can be given a date for hearing or (b) it can be ruled by the Court by agreement or (c) it can be struck out with or without orders.
It is neat way to keep a case moving along if one person is dragging their heels. There is nothing like a Court date to motivate someone into action.
mf