Program it into the FMS and let it decide how to enter, then it is the software programmer's issue.

I don't think it matters how you enter as long as you stay in protected airspace. But Chapter 5 of the AIM and the Chapter 10 of FAA instrument flying handbook on holding both say the same thing word for word about holding.

http://www.faa.gov/library/manuals/a...ers%208-11.pdf

While other entry procedures may enable the aircraft to enter the holding pattern and remain within protected airspace, the parallel, teardrop and direct entries are the procedures for entry and holding recommended by the FAA.

The way the AF reads things these days, recommended turns into a thou shalt. What does the FAA say about recommended? Probably just like any FSDO when you ask a question, the answer will depend on which check airman you ask and what his background is.