Word generates code that is hidden in your Word document to enable it to communicate with Mendeley. This code increases the file size and many publishers request that you remove this code when you submit your paper for publication. You should also remove the code when submitting a paper to Turnitin, UCL's plagiarism detection software.
You should only remove the code when you are sure you have finished editing your document.
As well as a requirement for submission, this also allows you to make small edits to your references in Word if required (useful if your output style meant a reference wasn’t displaying as needed). This process is not reversible so make sure you save the version without the field codes as a new document. Keep a copy of your original document with the field codes in case you need to go back and make further edits.
To save a copy of your Word document without Mendeley field codes, first select all the text including citations and the list of references (Using keyboard, type: Ctrl A). Right-click, using your mouse, and in the dialogue that appears, select: Remove Content Control.
Your document will have all Mendeley field codes removed, and is suitable for submission to Turnitin. (Please note: this process is non-reversible).