Account codes are often used to indicate hierarchies and relationships within an accounting structure. For example, group 6700 might be expenses for business taxes paid. 6710 could be real property taxes, 6720 municipal license taxes, 6730 district fire protection tax. In Manager, 6700 could be assigned to an expense group, while 6710, 6720, and 6730 would be individual account codes. (Group and total codes are separate sequences in Manager, but work just as well when they fit a bigger structure.)
This approach would handle @Davide’s desire for detailed account designations, just without letters and decimal points. Manager will accept codes up to 10 digits long.