In Adoption of Kelsey S. (1992) 1 Cal. 4th 816, the California Supreme Court acknowledged the limits of an unwed father's statutory rights. Kelsey's unwed mother planned to place the child for adoption at birth; the natural father objected, desiring to raise her himself. The father made "diligent and legal attempts to obtain custody of his child" (Adoption of Kelsey S., supra, 1 Cal. 4th at p. 821), but the mother gave custody of Kelsey to the prospective adoptive parents and refused to allow the father any contact with her. The father filed a petition to establish a parental relationship under former Civil Code section 7006; the prospective adoptive parents filed an adoption petition and a petition to terminate the father's parental rights under former Civil Code section 7017. The two proceedings were consolidated, and the trial court determined that Kelsey's best interest required termination of the father's parental rights. The Supreme Court found the Legislature expressly distinguished between "presumed fathers and fathers who attempt unsuccessfully to gain custody." (Adoption of Kelsey S., supra, 1 Cal. 4th at p. 827.) Because the mother had frustrated the father's attempts to attain the status of presumed father by receiving the child into his home, he was effectively denied the right to block the adoption under the statute. The court went on, however, to examine the constitutionality of the Legislature's clear intent "to provide natural fathers with far less rights than both mothers and presumed fathers have under California's statutory system." (Adoption of Kelsey S., supra, 1 Cal. 4th at p. 844.) After an extensive review of the case law, the court held the statutory definition of a presumed father in former Civil Code section 7004, subdivision (a) and the related statutory scheme were unconstitutional "to the extent they allow a mother unilaterally to preclude her child's biological father from becoming a presumed father and thereby allowing the state to terminate his parental rights on nothing more than a showing of the child's best interest. If an unwed father promptly comes forward and demonstrates a full commitment to his parental responsibilities--emotional, financial, and otherwise--his federal constitutional right to due process prohibits the termination of his parental relationship absent a showing of his unfitness as a parent. Absent such a showing, the child's well-being is presumptively best served by continuation of the father's parental relationship. Similarly, when the father has come forward to grasp his parental responsibilities, his parental rights are entitled to equal protection as those of the mother." (Adoption of Kelsey S., supra, at p. 849, If an unwed father fails to demonstrate a full commitment to his parental responsibilities, the statutes are constitutionally sufficient as applied to him. (Id. at pp. 849-850.) The Supreme Court then outlined the procedure to be followed when an unwed father seeks to assert his parental rights--the "Kelsey S. hearing." It clearly directed the trial court on remand to take evidence and decide "the threshold constitutional question of whether petitioner demonstrated a sufficient commitment to his parental responsibilities . . . in the first instance." (Adoption of Kelsey S., supra, 1 Cal. 4th at p. 850.) If the trial court found no such demonstration, "that will be the end of the matter" because the best interest question has already been determined. (Ibid.) If the trial court found the required commitment, however, it would proceed to the question of whether the father was statutorily unfit and thus could be deprived of his right to withhold consent. "Any finding of petitioner's unfitness must be supported by clear and convincing evidence. Absent such evidence, he shall be permitted to withhold his consent to the adoption." (Id. at p. 851.) The court emphasized the threshold nature of the consent determination. "If petitioner fails to establish on remand that he has a right to withhold his consent, there will be no question as to whether he should have custody of the child. If, however, the trial court concludes that petitioner has a right to withhold consent, that decision will bear only on the question of whether the adoption will proceed. Even if petitioner has a right to withhold his consent (and chooses to prevent the adoption), there will remain the question of the child's custody." (Ibid.) In Adoption of Kelsey S. (1992) the Supreme Court held that a biological father "has a constitutionally cognizable opportunity interest in developing a relationship with his child." (Adoption of Kelsey S., supra, 1 Cal. 4th at p. 844.) "The biological connection between father and child is unique and worthy of constitutional protection if the father grasps the opportunity to develop that biological connection into a full and enduring relationship." (Id., at p. 838.) Accordingly, this "statutory scheme violates the federal constitutional guarantees of equal protection and due process for unwed fathers to the extent that the statutes allow a mother unilaterally to preclude her child's biological father from becoming a presumed father and thereby allowing the state to terminate his parental rights on nothing more than a showing of the child's best interest. If an unwed father promptly comes forward and demonstrates a full commitment to his parental responsibilities--emotional, financial, and otherwise--his federal constitutional right to due process prohibits the termination of his parental relationship absent a showing of his unfitness as a parent." (Id., at p. 849.) In sum, the alleged father did not physically receive the child into his home because the birth mother sought to put the child up for adoption. (Kelsey S., supra, 1 Cal.4th at p. 825.) The court considered the alleged father's argument that "constructive receipt of the child is sufficient when the mother prevents actual receipt." (Id. at p. 828.) The court rejected that argument as a matter of statutory interpretation, because the plain language of the statute contemplates "actual" receipt rather than "attempted receipt or constructive receipt." (Id. at pp. 826, 830.) In the course of its analysis, the court discussed a pre-UPA case, In re Richard M. (1975) 14 Cal.3d 783 122 Cal. Rptr. 531, 537 P.2d 363, which suggested that constructive receipt might be sufficient. (Kelsey S., at pp. 827-828.) Kelsey S. declined to adopt that suggestion, pointing out that in Richard M. the father "had in fact received the child into his home, albeit briefly. The court therefore was not faced with the question before us, i.e., whether constructive receipt is sufficient when the mother prevents actual receipt." (Kelsey S., at p. 828.) Kelsey S. also pointed out that under the pre-UPA scheme there was a policy of liberal construction in favor of finding legitimation, so that children did not end up without a legal father. (Kelsey S., supra, 1 Cal.4th at pp. 828-829.) The court stated there was no need to "strain" to find a father through the doctrine of constructive receipt because in the case before it there were two competing fathers, so the child would end up with a legal father in any event. (Ibid.) Although the court declined to liberally construe the requirement in the case before it, 9 the court did not suggest that actual receipt of a child for a significant duration is required. To the contrary, the court discussed Michael U. v. Jamie B. (1985) 39 Cal.3d 787 218 Cal. Rptr. 39, 705 P.2d 362, in which the biological father sought temporary custody of the child in order to establish his presumed parentage claim. The court favorably quoted the decision as follows: "'Michael is a natural father, not a presumed father, because he has not yet received Eric the child into his home. If, however, he actually acquired physical custody, he could receive Eric into his home and thereby acquire the status of a presumed father. ... Thus the present controversy, although nominally about the temporary custody of Eric pending the adoption proceeding, will probably determine the fate of the proposed adoption.'" (Kelsey S., at p. 829, quoting Michael U., at p. 791; see also Kelsey S., at p. 842 stating that the superior court had "the authority to grant petitioner custody of his child so that he could qualify as a presumed father".) The clear implication is that the "receiving" requirement is a necessary formality, but not one that requires "receipt" for any particular duration. The Supreme Court held that "if an unwed biological father promptly comes forward and demonstrates a full commitment to his parental responsibilities--emotional, financial, and otherwise--his federal constitutional right to due process prohibits the termination of his parental relationship absent a showing of his unfitness as a parent." (Id. at p. 849.) Kelsey S. addressed the rights of a biological father who was prevented from attaining presumed father status by the child's mother. Kelsey S. is relevant only when the mother has prevented the biological father from becoming a presumed father. (See In re Kiana A. (2001) 93 Cal.App.4th 1109, 1117.) The dependency statutes do not refer to a Kelsey S. father, only to a presumed father within the meaning of Family Code section 7611. In Adoption of Kelsey S. "the court recognized a man attempting to satisfy the 'holding out' requirement for presumed father status 'may have been restricted, both legally and as a practical matter, in his ability to act fully as a father.'" (In re Jerry P. (2002) 95 Cal.App.4th 793, 806.) In Kelsey S., a biological father sought custody of an infant within two days of its birth. (Kelsey S., at p. 822.) The mother, however, wanted to place the baby for adoption. (Id. at p. 821.) The father participated in the custody, adoption, and paternity proceedings from their inception. (Id. at p. 836.) The mother and a court order (as well as the prospective adoptive parents, allegedly) prevented the father from bringing the baby into his home. (Id. at p. 825.) The trial court held the father was not a presumed father under Family Code section 7611(d)'s predecessor statute. (Kelsey S., at p. 823.) Therefore, the baby could be placed for adoption without the father's consent, if the court found adoption was in the child's best interest. The trial court found adoption was in the child's best interest and terminated the father's parental rights. (Kelsey S., at p. 823.) The Court of Appeal affirmed the judgment. (Ibid.) The California Supreme Court reversed, holding that Family Code section 7611(d)'s predecessor statute "and the related statutory scheme violates the federal constitutional guarantees of equal protection and due process for unwed fathers to the extent that the statutes allow a mother unilaterally to preclude her child's biological father from becoming a presumed father and thereby allowing the state to terminate his parental rights on nothing more than a showing of the child's best interest. If an unwed father promptly comes forward and demonstrates a full commitment to his parental responsibilities -- emotional, financial, and otherwise -- his federal constitutional right to due process prohibits the termination of his parental relationship absent a showing of his unfitness as a parent." (Kelsey S., supra, 1 Cal.4th at p. 849.) Significantly, Kelsey S. protection applies to "an unwed father who promptly comes forward" and "has sufficiently and timely demonstrated a full commitment to his parental responsibilities." (Kelsey S., supra, 1 Cal.4th at p. 849, ) Our Supreme Court stated: "Once the father knows or reasonably should know of the pregnancy, he must promptly attempt to assume his parental responsibilities as fully as the mother will allow and his circumstances permit." (Ibid, ) "When a biological father promptly comes forward, acknowledges paternity . . . , and seeks legal custody, the problem of locating the father simply does not arise." (Id. at p. 835.) The California Supreme Court held that Family Code section 7611 and the related dependency statutes violate an unwed biological father's federal constitutional guarantees of equal protection and due process to the extent they allow a mother or third person to unilaterally preclude the father from attaining presumed father status after he, upon learning of his paternity, promptly came forward and demonstrated a full commitment to his parental responsibilities. (Kelsey S., supra, 1 Cal.4th at p. 849.) In determining whether a biological father is a Kelsey S. father, the juvenile court considers his conduct before and after the child's birth, including whether he publicly acknowledged paternity, paid pregnancy and birth expenses according to his ability to do so, and promptly took legal action to obtain custody of [*9] the child. (Kelsey S., supra, 1 Cal.4th at p. 849.) The court also considers his willingness to assume full custody of the child. (Ibid.) If an unwed father fails to demonstrate a full commitment to his parental responsibilities, the statutes are constitutionally sufficient as applied to him. (Id. at pp. 849-850.) The California Supreme Court held that the statutory distinction between biological fathers and presumed fathers "is constitutionally invalid . . . to the extent it is applied to an unwed father who has sufficiently and timely demonstrated a full commitment to his parental responsibilities." (Kelsey S., supra, 1 Cal.4th at p. 849.) Specifically, the court concluded that federal constitutional guarantees of equal protection and due process require that an unwed father who is unilaterally precluded by the child's mother from becoming a presumed father under the statutory scheme be afforded the rights of a presumed father if he "promptly comes forward and demonstrates a full commitment to his parental responsibilities -- emotional, financial, and otherwise . . . ." (Ibid.) Under such circumstances, the court held that "the child's well-being is presumptively best served by a continuation of the father's parental relationship," absent a showing that he is unfit as a parent. (Ibid.) In determining whether an unwed father has "come forward to grasp his parental responsibilities" so as to afford him the same rights as a presumed father, a court must consider the totality of the circumstances. (Kelsey S., supra, 1 Cal.4th at p. 849.) The conduct of both the mother and the father, before and after the child's birth, are relevant to this determination. (Ibid. the father "must promptly attempt to assume his parental responsibilities as fully as the mother will allow and his circumstances permit".) As to the father, the court must look at whether he publicly acknowledged paternity, paid or offered to pay the pregnancy and birth expenses commensurate with his ability to do so and promptly took legal action to obtain custody of the child. (Ibid.)