//Henning....or if there is an even better approach to avoid overwriting output from different source blocks..any reason for this? I could try to write a patch but thought I'd ask first.However, I only see a org-babel-after-execute-hook but no org-babel-before-execute-hookI would like to add functionality so that org-babel-execute-src-block checks if in :results graphics FILE, FILE is already referred to by another source block and if so refuse to evaluate.I collaborate with different people on the same orgfile which contains many source blocks that generate graphics by e.g. :results graphics abc.pdfIt can happen that I or someone else accidentally create another independent source block that overwrites my abc.pdf which is of course very bad.