Maemo backends don't support Online Account capabilities. Actually OSSO ABook contacts support the following capabilities:

typedef enum
{
MC_PROFILE_CAPABILITY_NONE = 0,
MC_PROFILE_CAPABILITY_CHAT_P2P = 1 << 0,
MC_PROFILE_CAPABILITY_CHAT_ROOM = 1 << 1,
MC_PROFILE_CAPABILITY_CHAT_ROOM_LIST = 1 << 2,
MC_PROFILE_CAPABILITY_VOICE_P2P = 1 << 3,
MC_PROFILE_CAPABILITY_CONTACT_SEARCH = 1 << 4,
MC_PROFILE_CAPABILITY_SPLIT_ACCOUNT = 1 << 5,
MC_PROFILE_CAPABILITY_REGISTRATION_UI = 1 << 6,
MC_PROFILE_CAPABILITY_SUPPORTS_AVATARS = 1 << 7,
MC_PROFILE_CAPABILITY_SUPPORTS_ALIAS = 1 << 8,
MC_PROFILE_CAPABILITY_SUPPORTS_ROSTER = 1 << 9,
MC_PROFILE_CAPABILITY_VIDEO_P2P = 1 << 10,
} McProfileCapabilityFlags;