P.R. Laws Ap. tit. 32A, § IV, Rule 47
(a) In examining a witness for the purpose of attacking his credibility through a statement made by him in writing, no part of such writing need be shown or read to him, but the judge may, upon request, ask that the witness be shown the date and place of the writing, and the person to whom it was addressed. Upon request, the judge shall order that the writing be shown to the opposing counsel for inspection.
(b) Unless the interests of justice require otherwise, extrinsic evidence of a statement made by a witness which is inconsistent with any part of his testimony during the trial or hearing is not admissible unless the witness is afforded an opportunity to explain or deny said statement. This provision does not apply to “admissions” as defined in Rule 62.