Is there a standard way of referencing line numbers in a draft? I'm reviewing a manuscript with a two column layout that has line numbers on the left margin of the page, but not on the right. Like this:


How do I efficiently and effectively reference a particular line in the manuscript? Is there a standard way of doing it?

Currently I write "P1 C1 L12" to refer to page 1, left column, line 12.
Use whatever protocol you like, but explain your protocol to the editor and authors.  For example, you could include something like the following (quoting from someone else's review of one of my own papers):


  Throughout this review, "p.5(17)" refers to line 17 on page 5.