<%
f = taglib("/lib/form")
f.entry(:title => 'Implementation', :field => 'impl', :description => "RUBY[@GEMSET], such as '1.9.3' or 'jruby@foo'") do
  f.textbox
end
%>

<%
f = taglib("/lib/form")
f.entry(:title => 'Implementation', :field => 'impl', :description => "RUBY[@GEMSET], such as '1.9.3' or 'jruby@foo'. Alternatively, use '.' to load from .rvmrc, etc.") do
  f.textbox
end
%>

Add documentation to point out you can use '.'
Add documentation to point out you can use '.'