Reserves
Every account must hold a small amount of XRP that it can’t send: a base reserve, plus a bit more for each object it owns (trust lines, offers, and so on). Remove objects you don’t need to free that XRP back up.
Current: base 1 XRP + 0.2 XRP per objectTrust lines
To hold a token, you opt in with a trust line to its issuer. Each line counts toward your reserve. A line you didn’t add yourself, or a token you don’t recognize, is a reason to slow down. Don’t interact with it.
Tip: zero-balance lines can be removedDestination tags
Exchanges often share one address for many customers. The destination tag tells them which account is yours. Forget it, and your deposit can get stuck while support sorts it out. Always copy both.
Flag: RequireDestTagRegular keys & multisig
An account can authorize a second “regular” key, or a list of co-signers, to sign for it. These are powerful security tools. If one appears that you didn’t set up, someone else may be able to move your funds.
Check: SetRegularKey · SignerListSet