How to comment lines in rails html.erb files?

Note that if you want to comment out a single line of printing erb you should do like this

<%#= ["Buck", "Papandreou"].join(" you ") %>

ruby on rails notes has a very nice blogpost about commenting in erb-files

the short version is

to comment a single line use

<%# commented line %>

to comment a whole block use a if false to surrond your code like this

<% if false %>
code to comment
<% end %>