More evident malt flavor than in an ordinary bitter, this is a stronger, session-strength ale. Some modern variants are brewed exclusively with pale malt and are known as golden or summer bitters. Most bottled or kegged versions of UK-produced bitters are higher-alcohol versions of their cask (draught) products produced specifically for export. The IBU levels are often not adjusted, so the versions available in the US often do not directly correspond to their style subcategories in Britain. This style guideline reflects the "real ale" version of the style, not the export formulations of commercial products.