Limited Approval is a compromise of Vote-for-1 and Approval, that voters may find preferable to either.
A voter may indicate approval of more than one candidate, but with an upper limit on the number of approval votes each voter may cast.
Example: When the number of candidates is 7 or fewer, voters may be allowed to choose 2. When there are 8 or more, voters may be allowed to choose 3.
The simplest form of Limited Approval is Vote-for-2, which, as the simplest possible modification to improve Vote-for-1 elections, should be an achievable reform.