Curious why the tradeskill section of the character_list array is different

Going through the query results for some character information, I noticed that when I get to the tradeskills array it places the name of the tradeskill as an array inside of it with an attribute of the level. I'm wondering why, as all the other areas seem to place the name inside the array itself.

Code:

census.daybreakgames.com/json/get/eq2/character/880469212088?c:show=name,type,tradeskills&c:limit=1 Array ( [seconds] => 0.00526309013367 [limit] => 1 [returned] => 1 [character_list] => Array ( [0] => Array ( [name] => Array ( [prefix] => [first_lower] => ariya [last] => Ne'Nharma [suffix] => of Mistmoore [first] => Ariya ) [type] => Array ( [classid] => 13 [raceid] => 8 [level] => 29 [gender] => female [birthdate_utc] => 1208728918 [race] => High Elf [deity] => None [class] => Templar [alignment] => 0 ) [id] => 880469212088 [tradeskills] => Array ( [jeweler] => Array ( [level] => 90 ) ) ) ) )

Under type, it shows the name of the adventure class as:

type->class = Templar

but tradeskills doesn't have the same formatting.

tradeskills->jeweler->level (jeweler is an array with the attribute of level, not the name of the character's tradeskill profession)

there isn't a key:value pairing for the name of the tradeskill in the character list.

Just curious why it is different.