Hi Irina,
Commodity Business Calendar scheme has ASX.
for business center, the key point to consider is the scheme description == The codes are based on the business calendar location some of which based on the ISO country code or exchange code, or some other codes
The 4 letter constraint applies only when we are building something custom as per the rules below
Additional business day calendar location codes could be built according to the following rules: the first two characters represent the ISO country code [https://www.iso.org/obp/ui/#search], the next two characters represent either a) the first two letters of the location, if the location name is one word, b) the first letter of the first word followed by the first letter of the second word, if the location name consists of at least two words
Hope this clarifies