Why were abbreviations expanded in my abstract during copyediting/proofreading?

Journal style (and common copyediting practice) is to expand all "author-created" abbreviations; ie, any short form or initialism which does not appear frequently when searched in PubMed or Google. These abbreviations may appear freely throughout the main body of an article, but for purposes of readability should not be featured in abstracts, except for the exceptions listed in Which abbreviations don't need to be expanded?.

However, please note that we strongly discourage using too many "author-created" abbreviations in papers (except as listed under Which abbreviations don't need to be expanded?). We are an electronic journal and therefore do not have similar constraints to print journals with regard to word count and/or layout.

Related:

• Which abbreviations don't need to be expanded?