Quote from: remotemass on Today at 01:05:51 PM

What file format do you recommend to save a signed transaction to broadcast much later?

Any text-format will do. There's no need to make it more complicated.
Unless you want to make a QR-code out of it, in that case I'd go for PDF. Or just save it as GIF.

I suppose I should save it in a text file (.txt) or in a pdf file using just plain text with JSON or XML.

Quote

Actually, I don't have a clear idea of how does a signed transaction ready to be broadcasted and validated by the bitcoin network (and eventually entering the blockchain) does look like in plain text.

Like this:

Quote from: LoyceV on September 01, 2019, 09:24:37 PM

Signed Recovery Transaction

Code:

010000000126063a71fecd0c76fa7d31a561cbe95bf2c7e5da01ae04fed6a6e9dfbc80953e010000006a47304402201a16d89264518baca8f4959b446372c6ce91e8d1fbc0b7b48618aeb76113df33022040eb804bf7cd6519d01709066658251cef1822ff49fd07707e058a07b27b42f9012103f78766b4346bcec0f2ae92d7e132e6b321c47627f14356a704b3ce57169dcb4e000000000116260000000000001976a914cfdd1b997472bd0b668e7472d9708305f116994d88acc0270900

Quote from: remotemass on Today at 01:05:51 PM

But I want to learn about it. For instance, it would be very useful to be able to lock some coins and would be sent to someone else's address in the distant future if I did not change my mind in the meantime. This way I would know that if I die someone from my family would receive my coins in the distant future as I would not be able to change my mind after dying. Hope it makes sense.

See Using Locktime for inheritance planning, backups or gifts

Or play around with Coinb.in (don't enter any private keys on a LIVE website!).