Blanco is a very old man. Blanco is also a close friend of Fletcher. Blanco was imprisoned for murdering his wife. He featured heavily in the episode Happy Release where he and Fletch are in adjacent beds in the prison hospital, Fletch having broken his foot and Blanco having been diagnosed with a "tired heart". Also in the hospital is Norris (played by Colin Farrel), who is considered "scum" even by the other inmates, who had managed to con Blanco out of his only possessions: an antique silver snuff box, a Japanese wireless radio, and a musical box that played Waltzing Matilda when opened. Fletch manages to reacquire Blanco's possessions with the aid of Godber's help, and manages to get Norris, who had just been released, re-arrested after only one day by tricking him into trying to dig for "treasure" underneath the pitch of Leeds United.
Throughout his lengthy prison sentence Blanco continued to profess his innocence, and when parole was granted (in the episode Pardon Me) he refused, preferring the prospect of dying in prison to that of admitting guilt. When he is finally granted a pardon, Fletch warns him not to seek revenge on the person who really killed his wife. Blanco's response is an oft-repeated comedy moment:
"No. I know 'im wot did it. It were the wife's lover. But don't worry, I shan't go round searching for him, 'e died years ago. That I do know. It were me that killed him!".
Jason's role alongside Ronnie Barker in Porridge is just one in a long line of occasions on which the two have paired up. Another notable role for them was in Open All Hours. David Jason was originally considered for the part of elderly Lance-Corporal Jack Jones in Dad's Army; the role went to Clive Dunn.