Our OC does have a ‘Miscellaneous Expenses’ line in the budget but it is less than 1% of the total budget and I always write a “Treasurer’s Report” in which I explain what expenses were put against that line. Usually we do have a few minor random items that are genuinely miscellaneous and don’t fit any other budget line. Eg. recently we bought an updated, current edition of a book on meeting procedures that our first AGM in the 1970s had decided would be the rules for our meetings, there was a minor website cost to renew the domain name, and some minor printing costs for a couple of newsletters.
Worry if a substantial fraction of expenses is under ‘miscellaneous’ although it probably just means that the category should be broken up into several specific explicit purposes.