I put a label IN the planting hole so I will always know the name of my daylilies. I use a plastic knife, like you would get at a deli or use on a picnic. I write the daylily name on the blade with a Sharpie Permanent Marker, then for added protection, I put a piece of the clear Scotch Tape over the words. I place the tag just under the roots, so when I dig the daylily to divide, the tag is right there. No more lost ID's!
By putting the tag IN the hole, you eliminate the risk of broken or lost tags, or tags fading to the point you can no longer read them. Dogs, children, deer - they can't get to tags underground.
I bought a box of 500 plastic knives at Sam's Club years ago. They were very inexpensive. They also make great temporary tags for potted perennials, or for garden veggies. The don't take the winter well here in the north, so I would not use them above ground if you want them to last for more than a season or two. They are brittle in the cold. However, when placed underground, I've had them look like brand new after 10 years underground.
I have also used Impress-O-Tags the same way. I buy them by the 1000 right from Amekron. I use the 1" x 3-3/8" type, and write on them with an old ball point pen. The impression is still there years and years later.