The Society of Petroleum Engineers (SPE) produces publications for engineers worldwide. Clear writing is essential due to the international audience. SPE's style guide promotes clarity, conciseness, accuracy, and consistency. It provides guidelines on abbreviations, numbers, punctuation, and other elements of technical papers. While the style guide is intended for SPE's own publications, others may also find it helpful. The objective is to define SPE's treatment of style questions, not establish a broadly applicable industry standard.