I created a menu item of type edit instance. The instances are listed here as a table. However, I only want to display the first 3 columns here, because otherwise it is not very clear. How can I set this up?

Hello

Please check in OrdaSoft Joomla CCK - you set which column show in "Instance Manager" - in same place (CCK Fields Manager) as for Admin part and for Frontend.
If some field no need there - please unselect them at "CCK fields Manager' (You access it from any add Layout, when press button "add field"

BUT: we show there some important fields every time

Regards
OrdaSoft team

I just want to suppress the field in the table, that is displayed, when I click the edit instance menu item. I would then like to call up and edit the instance via the ID or the title - but then all fields should be displayed there.
Please see the screenshot before. The table-list is not very good to read. Better only the first two columns.

hello

First way and most right way in Joomla CCK Pro version - use "CCK instance manager", and set field which you need show in"CCK fields manager" - as we described above.

BUT
If you check edit instance in your Frontend Instance manager, you see link where will exist code:

where 379 - is ID of instance which user need edit

So In OUr Joomla CCK - you may create, exactly so layout for "Instance edit" as you need, You create it exactly as other layouts
Only In "Show instance" layout - you need add "custom PHP field" where to add "Edit link" created as in your Instance manager
so code will look like

Where
{your_link_for_instance_edit} - your_link_for_instance_edit from Instance manager from frontend without

$entityInstance->eiid - ID to instance which will need edit, in this example == 379. We will insert there ID of instance which you see for edit

Regards
OrdaSoft team

Please excuse me, but I didn't understand.
I created Layouts for "IM Requests". There are 8 layouts - 2 add and 6 show. When I create a menu item "Edit IM requests" I am asked for the entity. Which layout is the menu accessing now. Which layout do I have to edit and where do I have to insert the php code?
Could you do that for me, please? I will send you the access data by email.

1 Please create "show instance layout" - with 3 fields which you need show to client for layout edit.
2 Please create all instance layout and add layout(from step 1) as "attachment layout"
3 Please create menu for show layout 2 and set correct Access Right for it
4, In Layout from Step 1 - you need add "Custom Field" with PHP code, with "Link to edit' as I described in post before

Regards
OrdaSoft team