Complex sentence: Note again, that Black can delay playing... e5, for example 1.c4 Nf6 2.Nc3 Nc6 3.Nf3 e5 whereupon even though... e5 has been delayed, once it is played the defence is classified as a Reverse Sicilian.
Split into simpler sentences: Note again, that Black can delay playing... e5, for example 1.c4 Nf6 2.Nc3 Nc6 3.Nf3 e5. Even though... e5 may be delayed, once it is played the defense is classified as a Reverse Sicilian.