title: Documentation of squared bracket `[` function
body: <p>I have a function in R that looks somewhat like this:</p>
  
  <pre><code>setMethod('[', signature(x="stack"),definition=function(x,i,j,drop){
    new('class', as(x, "SpatialPointsDataFrame")[i,]) })
  </code></pre>
  
  <p>I use it to get a single element out of a stacked object. For the package I'm building I need a .Rd file to document the function. I stored it as [.Rd but somehow the R CMD check does not see this. It returns:</p>
  
  <pre><code>Undocumented S4 methods:  generic '[' and siglist 'MoveStack,ANY,ANY'
  </code></pre>
  
  <p>The <code>[.Rd</code> file starts with these lines:</p>
  
  <pre><code>\name{[}    
  \alias{[}
  \alias{[,stack,ANY,ANY-method}    
  \docType{methods}    
  \title{Returns an object from a stack}    
  \description{Returning a single object}    
  \usage{
    \S4method{\[}{stack,ANY,ANY}(x,i,y,drop)
  }
  </code></pre>
  
  <p>Any idea how I make R CMD check aware of this file?</p>