...The organization in question is already using a logo/icon of appropriate dimensions (roughly square). If that doesn't exist, then there's really not much that can be done, and the request will have to be ignored until such time that a logo/icon can be provided. An icon of appropriate resolution can be provided or linked to. Ideally, the provided file will be a vector file (e.g. SVG, EPS, AI) or a PDF with the vector file embedded. These files are all very easy to work with, and result in the most faithful reproductions of the icon.