From Bender's Immigration Bulletin: Charles Miller Obtains FOIA CBP IFM

CBP Inspector's Field Manual on the web
AILA member Charles "Chuck" Miller (a former INS attorney) managed to obtain much of the current IFM through a FOIA request. (Ongoing; he is still negotiating with CBP for further releases.) He has posted it to his website, linked here. Large file: 354 pages, almost 2MB, so download may be slow depending on your connection. Fully searchable with Adobe Acrobat. Chuck says Ch. 15 is especially interesting.