While Texas Rule of Evidence 404(a)(2) allows the admission of evidence concerning a victim's character or pertinent character traits, rule 405(a) limits the permissible method of proof to reputation or opinion testimony. See Tate v. State, 981 S.W.2d 189, 192 (Tex. Crim. App. 1998). Additionally, rule 405 provides that in all cases where reputation or opinion testimony is admissible, "on cross-examination inquiry is allowable into relevant specific instances of conduct." Tex. R. Evid. 405(a). The only time evidence of specific instances of conduct reflecting character is allowable is to counter or test the basis of opinion or reputation testimony given on direct examination. See Green v. State, 682 S.W.2d 271, 296 (Tex. Crim. App. 1984). This is generally done by "have you heard" or "are you aware" questions. See id. Rule of evidence 608 explicitly addresses a witness's general character or credibility for truthfulness. Dixon v. State, 2 S.W.3d 263, 271 (Tex. Crim. App. 1999) (opinion on rehearing); Tex. R. Evid. 608. A witness's credibility for truthfulness may be impeached only by opinion or reputation testimony and by proof of certain types of criminal convictions. Dixon, 2 S.W.3d at 271; Gonzales v. State, 929 S.W.2d 546, 549 (Tex. App.--Austin 1996, pet. ref'd); Tex. R. Evid. 608(a). Other than convictions for certain types of crimes, a witness's general character for truthfulness may not be impeached by proof of specific acts of conduct. Dixon, 2 S.W.3d at 271; Gonzales, 929 S.W.2d at 549; Tex. R. Evid. 608(b); see also 1 Steven Goode, Olin Guy Wellborn III & M. Michael Sharlot, Guide to the Texas Rules of Evidence: Civil and Criminal 608.1 (Texas Practice 2d ed. 1993).