[brewmarche]

I only knew about SECAM, where it’s even part of the name (Système Électronique Couleur Avec Mémoire)

[grishka]

You can decode a PAL signal without any memory, the memory is only needed to correct for phase errors. In SECAM though, it's a hard requirement because the two color components, Db and Dr, are transmitted on alternating lines, and you need both on each line.

[accounting2026]

Yes that is called "PAL-S". But the system was designed to use the delay-line method and it was employed since the inception (first broadcast 1967).