Plain language is writing in clear, concise language that is easy to read and understand. Whenever I hear the term plain language I am reminded of a lay summary I was once asked to edit. The stream of technical language (‘self-source bias’, ‘effect modifiers’, ‘peer context’, ‘latent class growth modeling’, ‘marginal structural models’, ‘propensity score matching’, ‘co-relative control designs’, ‘GIS analytic techniques’) made my head spin. What was the author thinking? Of course, a lay summary not written in plain language is not a lay summary. But why shouldn't plain language also apply to other kinds of medical writing?

As explained by Alistair Reeves in this issue of Medical Writing, writing in plain language does not come naturally, and it does not mean writing the way we speak or dumbing down what we write. It means using words that you expect your audience to understand and formulating sentences and paragraphs to make your text easy to understand. When writing for our peers, we assume that they know or can understand the technical terms that are a normal part of our lexicon. Even so, we can do them a favour by keeping long sentences and awkward passive constructions to a minimum. And we should never assume that only our fellow professionals will read what we write, or that our readers all have the same first language as we do.

Some medical writers, even experienced ones, argue that certain documents, such as those destined for regulatory agencies, must be written in language that is awkward and excessively technical due to supposed ‘rules’ or ‘standards’. This is a disturbing dogma that has developed – with no rules or guidelines to justify it. Regardless, in some hands, medical English has become understandable only to the writer and a few experts. Imagine that you are forced to read documents written in such language. Why should they not be easy to understand? And if you were a regulator, wouldn't you want to avoid lost time and headaches from having to decipher bad writing?

As Alistair Reeves also points out in his article, writing in plain English can be time consuming but can become automatic with practice. He goes into detail about what plain English means in the context of medical writing and invokes especially George Orwell's six rules for clear writing as they apply to medical writing, adding five useful rules of his own.

The failure of professionals to write in a way that ordinary people can understand led to the emergence of campaigning organisations such as Plain English Campaign, which has spent the last 35 years fighting ‘gobbledygook, jargon and misleading public information’.¹ It also forced governments to adopt firm measures. In 1999, the UK Lord Chancellor ordered civil courts to replace archaic terms with plain language alternatives.² Plaintiff was replaced with claimant and interrogatories with requests for information, and we all now have some hope of understanding what's going on. The US Congress went one step further, signing into law the Plain Writing Act of 2010, which requires that all documents issued by federal agencies be in plain language. Writing in this issue of MEW, John Parmer and Cynthia Baur describe steps the US Centers for Disease Control and Prevention (CDC) has taken to comply with both the act and CDC's own plain language agenda.

The above examples are from English-speaking countries, and plain language is often used synonymously with plain English. However, other countries have similar movement