"In the Falcon documentation, there is code provided by the authors, and within it, there is an implementation under the 'c' folder where they perform testing on their algorithms. They include a test with vectors; however, it does not match the size that, according to their specifications, it should have. For example, one vector is as follows:
static const char *const KAT_SIG_512[] = {
"cd3f225a65b2c6e155c2af799308af940212633fa519a4b4ddd22048ff8a7d06",
"sample 0",
"0900070058......."};
Where the first element is the nonce, the second is the message, and the third is the signature. In this test vector, the nonce has a length of 32 bytes. However, in the documentation, they state the following: 'nonce string r (40 bytes).' I hope someone can clarify this doubt for me."
Did not find in the documentation the reason why this nonce size can be used.