If you work with official and/or secure documents or with descriptions of how those documents are produced, you might be interested in this glossary published by the Council of the European Union (Consilium).
Included in the definitions of most terms are brilliant photos and diagrams which make understanding much clearer.
Important: to find the equivalent term in another language, use the number in grey to the right of the term definition (circled in the screenshots).
Below is a link to the English version of the glossary, but it’s available in the official European languages – all you have to do is insert your country code instead of “en” in the URL.
Here is an example showing how to amend the URL for the Spanish version: