Changes

$$lockasset <asset> prevent asset from being sold with $$sellall aliases: [lockasset, la]

$$unlockasset <asset> allow asset to be sold with $$sellall aliases: [unlockasset, ula]

Land is a special kind of asset that determines how many facilities you can build. Their price goes up the more land you already have. You can buy land the same way you buy other assets, but land cannot be sold.