Maintenance for the week of December 7:
• PC/Mac: NA and EU megaservers for patch maintenance – December 7, 4:00AM EST (9:00 UTC) - 8:00AM EST (13:00 UTC)
• ESO Website for maintenance – December 8, 9:00AM EST (14:00 UTC) - 12:00PM EST (17:00 UTC)
• PlayStation®4: NA and EU megaservers for patch maintenance – December 9, 6:00AM EST (11:00 UTC) - 10:00AM EST (15:00 UTC)
The item level will restrict the enchant you could add to it. You'll see these blanks more often at low levels. At higher levels, you'll see that jewelry almost always has a trait and will often have an enchantment on it. Set items will always have traits and enchants.