"The gravamen of [failure to appear in the second degree] is the violation of a release or security agreement." State v. Eastman, 112 Or App 256, 258, 828 P2d 484 (1992). 
Neither ORS 162.195 nor any other statute in ORS chapter 162 defines "release agreement." However, release agreements fit into an overall statutory scheme, comprised of ORS 135.230 to 135.295, which provides for the pretrial release of defendants in one of three ways: (1) release upon personal recognizance; (2) conditional release; or (3) security release. ORS 135.245. A defendant must sign and submit a release agreement to the court regardless of which type of release is involved. ORS 135.255; Sexson v. Merten, 291 Or 441, 445-46, 631 P2d 1367 (1981). 

http://law.justia.com/cases/oregon/court-of-appeals/2002/a111347.html