Quotes from the Course are usually given with the proper Second Edition reference numbers.
The following information, written to help people interpret references, should also be sufficient to help you construct them correctly for writing.
The reference system isn't perfect, but it works pretty well most of the time. I'll take several examples:
- T-20.VIII.1:1, "Vision will come to you at first in glimpses."
- W-pI.110.2:4, "It is enough to let time be the means for all the world to learn escape from time."
- W-pI.rIII.112.2:1, "I am the home of light and joy and peace."
- W-pII.2.3:1, "Salvation is undoing in the sense that it does nothing…"
- M-15.2:12, "Learn to be quiet, for His Voice is heard in stillness."
- C-5.5:7, "Some bitter idols have been made of him who would be only brother to the world."
The first letter represents the "book" from which the citation comes:
T=Text W=Workbook M=Manual for Teachers (main part) C=Clarification of Terms (last part of the Manual volume) S=Song of Prayer P=Psychotherapy pamphlet
The first number in most citations is the chapter, or in the Workbook, the lesson number. The Workbook citations, however, should always use the "part" reference as well (remember that it is divided into two Parts?). So "pI" is Part I, and "pII" is Part II. In almost every case this is extraneous information, but in a few cases it is significant. The last Workbook citation in my list, for instance, can't possibly be a reference to Lesson 2, which is in Part I, not Part II. If you see a reference starting "W-pII" with the next number being under 15, it is a reference to one of those "What is…" sections that are scattered through Part II every ten lessons. These citations, I think, are almost useless for locating anything; while it is relatively easy to flip to Lesson 237, for instance, who in heaven's name knows where to find "what-is" Number 5? You have to know that Part II starts with Lesson 221, preceded by "what-is" #1", and that there are ten lessons between each "what-is," so #5 would precede Lesson 261. Clear as mud? I think so too. But I digress too much. Let's leave the funny Workbook citations aside for the moment; the rest are easier.
In the Text the chapters are divided into sections, so there is a roman numeral indicating section, followed by a paragraph number, then sentence number.
T-20.VIII.1:1 indicates chapter 20, section VIII, paragraph 1, sentence 1. The sentence number should always be preceded by a colon in all citations.
The Manual (and its second part, the Clarification of Terms) has no sections (well, a few chapters have sections), so the references are usually chapter.paragraph:sentence.
A few sections in the Text have subsections, identified with letters; if present, they follow the section number in parentheses, for example: T-6.V(A).1:1. The "Laws of Chaos" section, the longest in the Text, even has sub-sub-sections.
Going back to confusing Workbook citations. Besides the "what is" sections, there are review sections. If you see an "r" followed by a roman numeral, it is referring to a review section. Again this is usually useless information, e.g. W-pI.rI.53.5:2, "Whatever I see reflects my thoughts," could just as easily be "W-53.5:2." You don't need the part or review numbers at all, but they are used. And for good reason. Some reviews have an Introduction, not part of any lesson; then the "r" number comes in handy (although you probably have to look in the Table of Contents to find the page number, unless you've memorized where the reviews fall between the lessons). Example: W-pI.rIII.Int.4:5, "But your practicing can offer everything to you." That also shows you how the "Introductions" are usually abbreviated, although sometimes you'll see "IN" instead of "Int." The most confusing of all are the Final Lessons section and Epilogue (both Workbook and Manual have epilogs). W-pII.FL.Int.2:1 means, "Workbook, Part II, Final Lessons, Introduction, paragraph 2, sentence 1." And "W-pII.EP" is how citations in the Epilogue begin.
The reference system has been added after the fact. It is a clumsy system, but it does serve to identify things uniquely; that's the best that can be said for it. And as foreign language editions proliferate, this will be the only way of referring to passages that can be trans-lingual. Page number references are old-fashioned and won't work for different editions of the Course.
FINDING 2nd EDITION REFERENCES in copies of the FIRST EDITION
My opinion is that most people with the First Edition ought to be able to follow 2nd ed references, but they may not know how. It takes a little work for them, as follows:
1. Go through the Text and number the titled sections in your book, and also, perhaps, in the Table of Contents. The number of sections in the book has not changed between editions. For any chapter that begins with an untitled few paragraphs, do not number that as section I; instead, mark it as "Introduction."
2. Given a Text reference such as T-4.II.1:1, the roman numeral "II" is the section number. Therefore, turn to chapter 4, section II. To locate the page number for this section, use your Table of Contents (which is why I recommend numbering that as well).
3. Now, count paragraphs. In the example it is paragraph 1, so that's easy. However, you might want to number the paragraphs in your book when you look up a reference, so they will be numbered for later referencing. Then, count sentences within the paragraph.
The hard part is numbering all the sections; counting paragraphs and sentences thereafter is usually fairly easy. There are several places where the method breaks down because there are several sentences and at least one paragraph that were left out of the First edition entirely, and the count will be off. But these are few and far between, and for the most part the method will work.