Dates are in ISO 8601 format, with or without time of day. Example: 2011-01-01 or 2011-01-01T01:00:00
Currencies are in ISO 4217 format (EUR, GBP, USD)
Languages are in ISO 639-2 codes (en, fi, se)
Countries are in ISO 3166 two letter format (GB, FI, SE)
Item-based operations take arbitrary number of items-parameters in comma separated format <fruugoProductId>,<fruugoSkuID>,<quantity>. Example: 764312,397530,1