[squee333]

I've been looking at vintage periodic tables, and I prefer older symbols such as A for argon, E for einsteinium, Mv for mendelevium, and Lw for lawrencium. I know, however, that they're no longer recommended by IUPAC. That said, I have seen periodic tables from after the dates of the IUPAC recommendations (1957 for A/Ar, E/Es, Mv/Md; ~1964 for Lw/Lr) that have the older symbols, such as this one https://www.google.com/books/edition/Materials_Science/3JEkBAAAQBAJ?hl=en&gbpv=1&dq=E+Fm+Mv+No+Lw&pg=PR2&printsec=frontcover and this one https://www.google.com/books/edition/DHHS_Publication_No_NIOSH/bjBx0drDo-wC?hl=en&gbpv=1&dq=E+Fm+Mv+No+Lw&pg=PA244&printsec=frontcover. What should I do, considering that I kind of want to use the older symbols but feel that I'd be breaking some sort of rule if I did?

Apologies if this is a silly question.

[Hunter2]

Why you want to use older outdated Symbols. Use the newer valid ones and everything is fine.

[Borek]

You can call oranges potatoes and potatoes oranges if you want, nobody can stop you from that. Just don't be surprised if you will be sold not what you want, or if people will start making faces behind your back.

Element symbols are unified to facilitate communication. Nobody can force you to use the ones recommended by IUPAC, but if you start to use your own nobody will understand you nor treat you seriously.

[matangiind]

Depends on your choice what to use. But make sure it is correct.

[simon55]

Why use older chemical symbols?