What is the test for a foster parent to be a "pre-adoptive" parent?

"To the ordinary fears in placing a child in foster care should not be added the concern that the better the foster care custodians the greater the risk that they will assert, out of love and affection grown too deep, an inchoate right to adopt. The temporary parent substitute must keep his proper distance at all times to himself." Matter of Spence-Chapin Adoptive Service v. Polk, 29 N.Y.2d 196, 205, 324 N.Y.S.2d 937, 945, 274 N.E.2d 431, 436 (1971).

Regardless of the nomenclature given them on various reports, the F.'s were and have been "foster parents," not "pre-adoptive."