Possible Clues:

• O, that would be one's allowance, in a manner of speaking
• Restrict the supply of
• Parcel out scarce food, say
• O, this allowance would be bespoke, perhaps
• A measured portion in times of scarcity
• A fixed quantity allowed to one person in times of scarcity
• Give one to a customer, e.g.
• Limit to a fixed amount, be sparing
• Is that all the pest is allowed over 23 down?
• O, in a manner of speaking, that's all you'll get