I have a print here that calls out 1" PVC buried 6" deep marked as "for future". From what I can tell, it is most likely for a sound system or some sort of PA. Would you consider that to fall under column 5 of table 300-5 (99 NEC) as "not more than 30-volts and installed with Type UF or in Other Identified Cable or Raceway"?

Would you argue the only way I could put it in is if it is called out for future irrigation or LV lighting?

This is an outdoor recreation-type area.