Modifiers matching obligation:

• financial,
• moral,
• safe,
• contractual,
• legal,
• private,
• secure,
• sovereign,
• primary,
• fixed,
• marketable,
• regular,
• public,
• signed,
• small,
• natural,
• ethical,
• scholarly,
• ongoing,
• outside,
• military,
• corporate,
• professional,
• basic,
• legislative,
• civil,
• governmental,
• political,
• monetary,
• economic,
• written,
• monthly,
• published,

Simple categories matching monthly:

• meeting,
• event,
• allowance,
• fee,
• expense,
• activity,
• terms,
• commitment,
• bill,
• data,
• amount,
• payment,
• gathering,
• sport,
• item,
• outlay,
• party,
• correspondence,
• benefit,
• expenditure,
• utility,
• business,
• deposit,
• adventure,
• magazine,
• earnings,
• interval,
• outing,
• essential,
• charge,
• tax,
• report,
• receipts,
• income,
• indicator,
• journal,
• objective,
• obligation,