Use of the equivalent looking Roman Letter...

[naraht]

What are people's opinion of documents that use the same looking letter in the Roman Alphabet in a list of Greek Letter Organizations online?

For example
1) Delta Zeta being the Greek Letter Delta followed by the Greek Letter Zeta, it is written as the Greek Letter Delta followed by a Roman letter Z or
2) Alpha Tau Omega being a Roman A, a Roman T and then a Greek Letter Omega rather than three Greek letters.

It does irritate me, and on Wikipedia whenever I find it, I correct it.