DarwinAwardWinner/el-get — comment on commit 7536d36407b45198d17e61d4d3d3cabdb729a2a9
File: el-get-custom.el line 325
By tkf:

> in contrast to simply using the `:branch' property, which will cause el-get-to try to merge your local changes

Ah! Now I see why `:branch` exists!