Proper way to denote array data type for phpDocumentor?

Both methods are technically correct, but this one is considered 'better' because it's more specific (int and integer are interchangeable):

@return int[]

Documented here:

http://www.phpdoc.org/docs/latest/guides/types.html

At the moment of writing this answer, these are the accepted ways of phpDocumentor (and probably other PHPDoc implementations) to denote an array:

1. unspecified, no definition of the contents of the represented array is given. Example: @return array

2. specified containing a single type, the Type definition informs the reader of the type of each array element. Only one Type is then expected as element for a given array. Example: @return int[]
   
   Please note that mixed is also a single type and with this keyword it is possible to indicate that each array element contains any possible type.

3. specified containing multiple types, the Type definition informs the reader of the type of each array element. Each element can be of any of the given types. Example: @return (int|string)[]