Can QR Codes link to PDF files or any website?
Yes, QR Codes can link to any URL, so they can to to any website or file, like a PDF file that can be downloaded with a URL.
The problem with linking to a file is that most people will be scanning with a mobile device and downloading a .pdf could be problematic due to the file size and also reading .pdf files on a mobile phone is a horrible user experience.
We try to discourage people from linking to another website other than Plants Map for plant information because once the QR Code is created, it can't be changed and so if the external website updates their software, many times their URLs change and break the QR Code. The second reason is that since QR Codes are scanned with a mobile device, many websites can detect that a mobile phone is being used and they change the URL on the fly from something like www.website.com to m.website.com (the m. is to deliver a mobile version) and the QR Codes break.
We have created a way to have a short permanent URL for each plant page that never changes even if the plant page is updates or renamed.
What were you trying to share? We have a ton of options for displaying information about plants but we also have a lot of users who build Collections to talk about rocks, animals, habitats, etc. There are a lot of possibilities but I guess I'd need to understand what you are thinking about to be more specific.
Here is Tracy's plant library and if you click on a few of them you can see that you can store as many photos as you'd like and include a long story with links to other sites (and use what we call Reference Links in the Plant Details tab) to link to one or more external websites.
https://www.plantsmap.com/tracy-blevins/plants
A plant can be included in one or more Collections where you can write a story about your grouping of plants and include more photos.
https://www.plantsmap.com/tracy-blevins/collections
Collections can be further subdivided into SubCollections where you can further organize your plant library.
Go here and click the Subcollections tab:
https://www.plantsmap.com/collections/165