Frozen allotments are amounts that have been approved by Parliament but that the Treasury Board—as a group of ministers—has decided to freeze so that departments cannot access them. You can freeze these amounts for a variety of reasons—waiting for certain conditions to be met, for example, or to ensure that these amounts don't get spent and are reallocated to other initiatives. That's in a nutshell what frozen allotments are usually done for. It's two broad categories.
We found that they're amounting to almost $12 billion in 2023-24, and $7 billion of that is to be reprofiled to subsequent years. These are amounts that won't be spent in the current fiscal year but in subsequent fiscal years, and about $500 million of that is repurposing government spending.