Quote from: PrivacyG on Today at 11:23:05 AM

My main concern was if I somehow mistyped the shortened form of a word or two. Then I would be screwed. Imagine I somehow mistyped 'RETI' from 'retired' as 'RETR' which works as 'RETReat'. The mistake is not impossible to commit, all you need is a little bit of lack of attention and accidentally skipping the letter 'i'.

Then you are left with 11 correct short forms and 1 mistype. When you will need to restore your wallet you will quickly find out it is not the correct seed. If you have the full words, finding out you misspelled 'retired' as 'retred' is easy. Now if you had 12 words and they are all short form, how will you find out?

In the case of a wallet generated with the BIP39 standard, the correct thing to do, if you want or need to use only 4 letters for each word, is to use the first 4 letters

You cannot abbreviate the word. You have to use exactly the first 4 letters as they will not be repeated. There is only one possible option and you'll be safe to use this wallet

Quote from: BlackBoss_ on Today at 11:10:25 AM

I don't know about a secret of first 4 letters but I knew that in Electrum wallet, when you type words for its wallet seed, you will be recommended a list of possible words. This feature is available for both Electrum wallet software on desktop and mobile devices.

Additionally, you can always find words in BIP word lists for example word list for BIP39.
https://github.com/bitcoin/bips/blob/master/bip-0039/english.txt

I don't think complicate your wallet backup methods is good idea.

If you want to back up your wallet safely, read How to back up a seed phrase?

There are some cases where you need to reduce the number of characters to store your seed, such as using a Cryptosteel, where it would be impossible to write down all the complete words, so the only way to do this is to reduce it to 4 letters.