From the Commentary to 226.14;
Periodic rates. No explicit tolerance exists for any periodic rate as such; a disclosed periodic rate may vary from precise accuracy (for example, due to rounding) only to the extent that its annualized equivalent is within the tolerance permitted by ยง226.14(a). Further, a periodic rate need not be calculated to any particular number of decimal places.
_________________________
The opinions expressed are mine and they are not to be taken as legal advice.