If interested, following links might help, and these are the official sources / links from API (American Petroleum Institute):
ILSAC: https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-ilsac
Gasoline: https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-gasoline
(API SM, SN, SN Plus, etc. are for Gasoline engines only!)
Diesel C Categories: https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-diesel-c-categories
Diesel F Categories: https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-diesel-f-category
(I would urge all interested to go through the links, at least for once, and read for yourself)
YES. ACEA A3/B4 has been mentioned, which as per European Automobile Manufacturers' Association (or Association des Constructeurs Européens d'Automobiles in French) is a stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & DI Diesel Engines, but also suitable for applications described under A3/B3.
For A3/B3, it has been written that:
ACEA A3/B3 Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & Diesel Engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of Low Viscosity Oils, and/or for severe operating conditions as defined by the Engine Manufacturer.
(Source of the info: https://www.oilspecifications.org/acea.php )
(When I had said that 5w-40 Liqui Moly is optimum for gasoline engines, it was based on area of application, mentioned in product data sheet shared above)
These all must be linked and read together. One can not take some bits and pieces from one part, and rest from other, etc.
In your case, I would sincerely suggest to use that engine oil grade (like 5w-40, 10w-40, 15w-40, etc.) which has been recommended by your diesel engine's manufacturer, and has also been mentioned in your car's owners / users manual.
For Diesel engine oil categories, you must use that latest one, which meets / exceed OEM requirements.
Brother Caltex Delo Gold and Liqui Moly are two entirely different companies in my opinion. First decide about the grade, then category, and lastly for the brand.
I would prefer Caltex over Liqui Moly, given same conditions set.
I hope, it helps. Thank you.