The OMB (“o” stands for opaque) report: OMB Report Pursuant to the Sequestration Transparency Act of 2012 (P. L. 112–155), Appendix B. Preliminary Sequestrable / Exempt Classification, classifies accounts as sequestrable, exempt, etc.
One reason to be “exempt” is funds were already sequestered elsewhere in the budget. Makes sense on the face of it.
But for 487 entries out of 2126 in Appendix B, or 22.9%, are being sequestered from some unstated part of the government.
Patrick makes his analysis of Appendix B available for download as a CVS file. I took it and turned it into this handy online spreadsheet. Read more about Preliminary Sequestrable Exempt Classification by OMB Account and Type of Budgetary Resource