diff --git a/docs/src/extensions.md b/docs/src/extensions.md
index 48c7d41af..65b432ac1 100644
--- a/docs/src/extensions.md
+++ b/docs/src/extensions.md
@@ -1,6 +1,7 @@
 # [`ExtendableFEMBase`](https://github.com/chmerdon/ExtendableFEMBase.jl/) Extension
 
-sometextthatexplainssomething
+The extension for [`ExtendableFEMBase`](https://github.com/chmerdon/ExtendableFEMBase.jl/) extends the funcitons below for solution types of [`ExtendableFEMM`](https://github.com/chmerdon/ExtendableFEM.jl/).
+The name of the extension originates from the solution type `FEVectorBlock` that is definded in `ExtendableFEMBase`.
 
 ```@docs
 edgevelocities(grid, vel::FEVectorBlock; kwargs...)