It's not always so simple, as I found when I bought a "flexible" ticket from Germany to South Tyrol online. The ticket couldn't be printed, but had to be posted

It's not always so simple, as I found when I bought a "flexible" ticket from Germany to South Tyrol online. The ticket couldn't be printed, but had to be posted (an extra 4.50 euros!). It also wasn't possible to cancel online, but had to be posted back to the train company with a post mark dated before the date of travel. I tried to cancel it at the train station, but again this was not possible.