FMV of inherited real estate sold within 6 months of death

This question relates to the sale of inherited real estate and the acceptable methods for determining capital gain/loss treatment on an estate's 1041 return.  I understand that a property's basis for cap gains purposes is fair market value as of the date of death, which is usually determined by an appraisal or through tax assessment. But, I recall reading somewhere that if the property is sold within six months, the IRS would consider the purchase price as FMV. Is this true and can anyone point me to the source of this guidance?