Style guide

A Style guide is a set of uniform stylistic rules and conventions for publications

Of which
Initial capitals ... should be used sparingly a special attention to Acronyms. As general rule - do not use upper cases unless required by grammar.
 * 10.4. Upper and lower case

Internal

 * Interinstitutional Style Guide (Europa, Publications Office), Welcome to the style guide!
 * DG ECFIN, styleguide
 * DGT, English Style Guide, Seventh edition: August 2011, Last updated: March 2015
 * DGT, Country Compendium, A companion to the English Style Guide, March 2015
 * Eurostat, The Eurostat publications graphical style guide - 2011 edition

External

 * The Economist Style Guide
 * The Guardian and Observer style guide