OPINION OF THE COURT
HUTCHINSON, Justice.James Cox appeals by allowance Commonwealth Court’s order affirming the Pennsylvania Board of Probation and Parole’s (Board’s) order denying him credit for time spent in an in-patient drug treatment program at Eagleville Hospital. At issue is whether appellant was, in the language of the statute, “at liberty on parole” while in that program. We are handicapped in dealing with this issue of first *616impression by a deficient factual record. Faced with those deficiencies we remand this case to the Board for development of a factual record sufficient for review of whether the Eagleville program is a prison equivalent precluding the conclusion that appellant was “at liberty on parole.” However, since appellant agreed to attend Eagleville as part of his parole program, his attendance there is presumed to be “at liberty on parole,” and on the remand it will be up to him to show that Eagleville’s in-patient drug treatment program presented an environment so restrictive that he should get credit for time spent in it. Moreover, the Board’s resolution of that issue seems to us largely in its discretion and should not be disturbed unless the record shows the Board’s action to have been arbitrary.
The relevant facts can be briefly stated. Appellant was convicted of burglary in 1974 and sentenced to prison for 1 to 5 years. The Board, by order dated June 16, 1976, granted appellant parole on this sentence. That parole commenced on August 26, 1976.1 Pursuant to 37 Pa.Code § 63.5,2 the Board imposed as a special condition of appellant’s parole attendance at Eagleville Hospital’s in-patient *617drug and alcohol treatment program, defining failure to successfully complete that program as a parole violation.
Appellant did successfully complete the treatment program and left Eagleville to continue his parole on the street.3 He was arrested in June of 1977 on burglary and related charges. He escaped from custody and was re-arrested in November, 1979. He then pled guilty to reduced charges stemming from the 1977 arrest and received sentences of county probation. He also pled guilty to the escape charge and was sentenced to 1 to 3 years imprisonment.
The Board held the required parole violation and revocation hearing. Cox was represented by counsel at this hearing. He was recommitted to serve the unexpired term of his original 1 to 5 year sentence as both a convicted and a technical parole violator. In the recommitment the Board recomputed appellant’s maximum term under that sentence, under Section 21.1 of the Parole Act,4 without giving him credit for time spent at Eagleville. It held that he was “at liberty on parole” while there. The Board subsequently denied appellant’s petition for administrative relief. Commonwealth Court, 78 Pa. Commonwealth Ct. 183, 467 A.2d 90, affirmed.
Section 21.1 of the Parole Act provides, in relevant part: (a) Convicted Violators. Any parolee under the jurisdiction of the Pennsylvania Board of Parole released from *618any penal institution of the Commonwealth who, during the period of parole or while delinquent on parole, commits any crime punishable by imprisonment, for which he is convicted or found guilty by a judge or jury or to which he pleads guilty or nolo contendere at any time thereafter in a court of record, may, at the discretion of the board, be recommitted as a parole violator. If his recommitment is so ordered, he shall be reentered to serve the remainder of the term which said parolee would have been compelled to serve had he not been paroled, and he shall be given no credit for the time at liberty on parole.5
61 P.S. § 331.21a (emphasis added). We have never conclusively defined “at liberty on parole,” nor have we had the opportunity to pass upon whether persons attending treatment programs like Eagleville’s are “at liberty on parole.” We have previously interpreted the phrase to include “street time,” though the concepts are not synonymous. See Young v. Commonwealth Board of Probation and Parole, 487 Pa. 428, 409 A.2d 843 (1979). We made this clear in Hines v. Pennsylvania Board of Probation and Parole, 491 Pa. 142, 420 A.2d 381 (1980), where we held that “at liberty on parole” included time spent on constructive parole. We said:
Hines next asserts that he is entitled to credit against his original sentence for the one year spent on constructive parole, citing Section 21.1 of the Parole Act, 61 P.S. § 331.21a(a),
Hines argues that because he was in prison while on constructive parole, he was not “at liberty on parole.” In Haun v. Cavell, 190 Pa.Super. 346, 353, 154 A.2d 257, 261 (1959) the Superior Court addressed this question: *619What the legislature must have intended by “at liberty on parole” is not at liberty from all confinement but at liberty from confinement on the particular sentence for which the convict is being reentered as a parole violator. Any other interpretation would be in conflict with other provisions of the statute, and with the long established policy of the Commonwealth. During the time that a convict may be on parole from a particular offense he might be confined in a Pennsylvania prison on another offense, or in a prison of another state, or in a federal prison, or in a mental institution, or in an enemy prison camp during a war. It was not the intent of the legislature to have the words “at liberty” to mean freedom from confinement under all these and other conceivable circumstances. (Emphasis supplied).
We approved this construction of the Parole Act in Commonwealth ex rel. Jones v. Rundle, 413 Pa. 456, 199 A.2d 135 (1964) (per curiam). Accordingly, Hines was “at liberty on parole” from his first sentence while incarcerated on his second sentence from August 29, 1975 to August 29, 1976, and is not entitled to credit against his original sentence for that one year on constructive parole.
Id., 491 Pa. at 148-149, 420 A.2d at 384.
Appellant did not enjoy the greater freedom of “street time” while at Eagleville, but he was restricted from leaving Eagleville under the special condition arising out of his original sentence, a restriction of liberty presumably less onerous than constructive parole. We are therefore left with the need for a factual determination as to the nature of the Eagleville program and whether the restrictions on appellant’s liberty there were the equivalent of incarceration entitling him to credit for the time spent in the program. The majority of jurisdictions which allow credit on backtime for time spent in rehabilitation programs examine the specifics of the program to make this determination. See Annot. 24 A.L.R.4th 789 (1983) (credit for back time on probation violations).
*620Any effort to review this factual question now is defeated by the inadequate record before us. Appellant’s assertion that he was not “at liberty on parole” because a premature termination of the Eagleville program would constitute a parole violation must, without factual support, fail. All forms of parole involve some restraint on the parolee’s liberty,6 and non-compliance with them can result in arrest and recommittal as a technical parole violator. It is appellant’s burden, on remand, to show the specific characteristics of the Eagleville program that constituted restrictions on his liberty sufficient to warrant credit on his recomputed backtime, and persuade the Board of that fact. Moreover, we will not interfere with the Board’s determination of that issue unless it acts arbitrarily or plainly abuses its discretion. See 2 Pa.C.S. § 704; Bradshaw v. Commonwealth, Pennsylvania Board of Probation and Parole, 75 Pa. Commonwealth Ct. 90, 461 A.2d 342 (1983).
Nevertheless, the Board must help in providing a record which makes effective appellate review possible. Simply because parole status must be voluntarily accepted by the prisoner, and the conditions of his parole are known to him when it is accepted, we cannot conclude, as the Board seems to intimate, that he is automatically “at liberty on parole.”
The Board imposed special conditions on appellant’s parole, conditions beyond those generally imposed on parolees. While the Board had the statutory authority to impose these conditions, the specific programs at Eagleville may have been so restrictive that they require the granting of credit. Other programs may not require such credit. We cannot make an informed determination of this issue on the record before us. Therefore, we reverse the order of *621Commonwealth Court and remand this case for further proceedings consistent with this opinion.7
Order of Commonwealth Court reversed and case remanded to the Board of Probation and Parole for proceedings consistent with this opinion.
PAPADAKOS, J., files a dissenting opinion in which LARSEN, J., joins. FLAHERTY, J., did not participate in the consideration or decision of this case.. One of the many deficiencies in the record in this case is a lack of a copy of the Board’s order granting appellant parole to Eagleville. A further gap in the record concerns the precise date of Cox’s entry into Eagleville.
We have assumed that the parole order was dated June 16, 1976, because appellant does not dispute this date. We have further assumed that he entered Eagleville on August 26, 1976, despite earlier, pro se, filings which give a date of August 23, 1976, because both the Commonwealth’s and petitioner’s counselled brief use this date.
Similar uncertainty exists about the date appellant left Eagleville.
See note 3, infra.
. 37 Pa.Code § 63.5 states as follows:
(a) Parolees shall comply with any special conditions which are imposed by the Board or which are subsequently imposed by the parole agent.
(b) If problems arise or questions occur concerning the conditions of parole, the parolee shall consult with the parole agent, as it is the responsibility of the latter to help the parolee in the interpretation of the conditions of parole. If a parolee is unable to contact his parole agent, he should contact the agent in charge of the district parole office.
. The record before us lacks any evidence as to the date on which appellant left Eagleville. Appellant claims he left on February 1, 1977. The Commonwealth claims that Cox completed the required treatment program on October 17, 1976, on which date he received a regular discharge from Eagleville. The Board alleges that Cox then entered the candidate program at Eagleville, a voluntary program of treatment, and remained therein until February 1, 1977.
As with the date of commitment of appellant to Eagleville, neither Cox nor the Commonwealth has provided documentary evidence to support their respective claims. This issue must ultimately be determined by the Board so that any back-time that is due can be properly calculated.
. Section 21.1 of the Act of August 6, 1941, P.L. 861, added by Section 5 of the Act of August 24, 1951, as amended, 61 P.S. § 331.21a.
. Our regulations arguably treat the underlined language as requiring credit in the absence of liberty. Such treatment is in accord with the case law elsewhere. Such construction is not a logical requirement of the language, but we will defer to it on the authority of those regulations and the reasoning of the cases. See 37 Pa.Code § 65.5(4); Lock v. State, 609 P.2d 539 (Alaska 1980); accord, 42 Pa.C.S. § 9760 (allowing the sentencing court to award credit for time previously spent in custody) (not cited in briefs).
. All parolees are subject to restriction on travel, place of residence and possession and use of weapons, and in addition must maintain regular contact with the parole supervision staff. See 37 Pa.Code § 63.4. In addition, special conditions of parole such as those imposed on appellant are authorized. See 37 Pa.Code § 63.5.
. In this regard we note that the Board itself concedes that “the record in this case provides no information on what restraints, if any, were imposed on Cox at the Eagleville Hospital, ...” Brief of Appellee at 6. They argue, however, that an examination of these facts is necessary only if we apply Commonwealth v. Mallon, 267 Pa.Superior Ct. 163, 406 A.2d 569 (1979) and Commonwealth v. Usher, 264 Pa.Superior Ct. 435, 399 A.2d 1129 (1979), interpreting the term "custody” under a prior statute relating to probation.
By this contention the Board seems to argue for a per se rule barring any credit on backtime for time spent in a rehabilitation program while on parole. We decline the Board’s invitation to pass on the propriety of Usher and Mallon, cases which granted credit for time spent in drug rehabilitation programs as conditions of probation, not parole. Furthermore, given our past unhappy experience with per se rules, we decline to adopt one in the present case, on so scanty a record.