What are some creative uses for barcodes (usually QR Codes)?

I feel that barcodes (usually QR Codes) are underutilized; I forgot about them until I saw this post.

• I think barcodes could potentially be used to quickly transmit preset information to war victims.

• They could be used to transmit information on platforms that censor: Sharing Lemmy posts on Reddit (even though it's currently redundant due to federation). (I just thought of this.)