Question about Ayu's A single
 

I have an question to ask about Ayu's A single.

I am confused about what ayu-mix.com said about underside cat number on the CD ( Here is the website to see what I am talking about: http://www.ayu-mi-x.com/modules.php?...howpage&pid=28).
They said that the Gold limited edition adds a C right next to the underside cat number(AVCD 30050C). So I am wondering what is that C thing?

My green limited edition A single also has that "C" thing but my blue one has a B (AVCD 30050B).

Here's the underside Cat number for all the 7 different versions.
30050
Black, Gold

30050A
Red

30050B
Blue

30050C
Green, Gold CD

30050D
orange

When avex gives out subcategory to the release, it basically meant different versions (or covers as seen on recent release). And basically it just means that they're different on the tracklist for the A singles.
30050 and 30050A basically just mean track listing is monochrome 1st.
30050B starts with too late.
30050C starts with Trauma.
30050D starts with End roll.
Hope this ans ur question~

Thank you! I didn't know this :D

*put into website* :innocent

thank you Kinix. That answered my question:D