The Importance of Labelling

As I mentioned the other day, I recently sowed two trays of onion seeds. They were of two different types. One was "Ailsa Craig", a brown type, and the other was "Long Red Florence" (a red type, obviously!). Unfortunately I made a real rookie error: I forgot to label them. Actually, to be honest, I didn't forget, I just didn't bother. I thought it didn't really matter, because they would both be treated in the same way, and once they got to the transplanting stage it would be obvious which was which. However...
One lot has germinated very well:

I sowed a "pinch" of seed (about 5 or 6) in each module, and they seem to have all come up.

This is the other tray:

One solitary seed, in one of the 15 modules has germinated (dare I say "...so far"?)

I suppose they may still appear, since it is only ten days since I sowed them, but I'm not very optimistic. The really annoying thing is that if I knew which variety was which, I could get a second batch sown before it's too late. I rather suspect that the No Shows are the Long Red Florence, because they were seeds from 2017, whereas the Ailsa Craig ones were from 2018. This would be a big shame, because I am very fond of the long red ones, which make a really great salad ingredient.
And all because of the absence of one of these...

Seriously, labels like this cost only pennies (mine were 50 for £1 in Wilkinson's) but they can save a lot of heartache. I know you may say "But they're plastic, and plastic is bad", but my response is that plastic labels are very durable and can be made to last for many years. I clean mine with White Spirit and an old Brillo pad, and reuse them several times, so I consider their use to be justified.