(Expanded translation of https://mastodon.com.pl/@HaTetsu/114754973655418031)
Looks like no more riding #PKPIC trains on urban transport tickets in #Łódź starting July, probably. According to Rynek Kolejowy (https://www.rynek-kolejowy.pl/wiadomosci/lodz-nie-zawrze-porozumienia-biletowego-z-pkp-intercity--123791.html), the city decided not to negotiate the separate agreement PKP Intercity wanted, having apparently concluded it should be the voivodeship or ŁKA that handles these things… While regional trains run by ŁKA, Polregio and KW are still in scope and seem to run at fairly reasonable, if not urban rail, headways, it's still a shame. In Switzerland it isn't so weird to take a short IC ride on a local ticket…
ŁKA tickets can still be used on PKPIC between Ozorków, Zgierz (no Stryków line), Koluszki and Pabianice as before - the whole thing started when (I'm fairly sure) that agreement was renewed and PKPIC had it reworded to only apply to ŁKA tickets in particular and not tickets valid on ŁKA, a principle I'm pretty sure was introduced due to a bunch of track works that reduced capacity for locals (and Łódź was also doing a lot of track works on the tram system).
For the last few years, Łódź was very unusual among Polish cities in having this universal recognition of tram/bus tickets in all trains within city limits, though it's also fairly unique in that it has no single main station in the city center which is the obvious place to take all the trains from, they're still building a tunnel to make that happen. Instead, railways form… not quite a ring, more of a weird teardrop shape around the city (missing curves in Zgierz and Widzew mean you have to change directions at least once, if you want to serve Dąbrowa and Zarzew twice, to circle the city), leaving them a unique, though less generally useful, niche.
And in case you're asking how validating paper bus tickets works/ed on PKPIC, the answer is simple: either come with an already validated ticket, or… simply write the date and time (DD.MM.YYYY hh:mm) in something permanent (I assume a ballpoint pen is sufficient) and board!
