I have copied and pasted what the 2nd edition BOS says about it, but really want the 3rd - TIA

Here is what my BOS says (not sure if 2 or 3) - this is from Benchmark KB

Drug terminology: Use lowercase abbreviations with periods for Latin abbreviations that are related to doses and dosages. Do not use abbreviations found on the "Dangerous Abbreviations" list from ISMP (See 9.3.2—ISMP Recommendations—above). Avoid using all capitals because they emphasize the abbreviation rather than the drug name. Avoid lowercase abbreviations without periods because some may be misread as words. Do not translate.

Note: We have inserted a space after the numeral 4 in q.4 h. on the advice of ISMP so that the number is more easily and clearly read. Invalid Latin abbreviations such as q.a.m. (every morning) and mixed Latin and English abbreviations such as q.4 hours (every 4 hours) have become commonplace. However, as with all abbreviations, avoid those that are obscure (like a.c.b. for before breakfast) or dangerous. For example, b.i.w. is both obscure and dangerous. It is intended to mean twice weekly but it could be mistaken for twice daily resulting in a dosage frequency seven times that intended.

Here is what it says about terms dictated in full - Amber

Do not use an abbreviation when a term is dictated in full. Exception: Units of measure.

Some facilities allow for the abbreviation of dosage instructions when dictated in full. AHDI does not recommend doing this arbitrarily unless the provider/facility clearly has a preference for this practice. If facility preference is unknown, transcribe in full as dictated. If facility preference dictates abbreviation of these terms, even if dictated in full, be careful not to use any of the dosage abbreviations that appear on the dangerous abbreviations list (See 9.3—Dangerous Abbreviations—below).

It is the 3rd edition - just found it - Amber