The hurricane center does not use certain letters of the alphabet, including X, Y and Z, because there are so few names begin with those letters. (realclimate.org)
There are no mods, just an automatic filter that looks for certain letter combos. (religion.blogs.cnn.com)
For example, anomalies in the content that can be added during conversion to plain text include random spaces between certain letters. (bbebooksthailand.com)