This episode has no closing credits, save for the title "Blackadder" (not "Blackadder Goes Forth") and the copyright date, over a field of poppies.
The end credits for the final episode are abrupt. After we see Blackadder and co. go over the top to their deaths, the music goes to a slow, mournful rendition of the main theme, and the scene shifts slowly to a shot of a real-life WWI trench, as it appears today -- a poppy-decked hill with the trench only barely visible. There is no ending credit roll, and instead, the Blackadder Goes Fourth logo and the BBC logo and copyright date appear unobtrusively in a corner.