According to information found on the internet, as of 2012, DARF has followed the pattern created by febraban. The layout can be found here:
link
The collection with the Numbered Darf was started in April 2012.
This is Darf issued by system (there being no possibility of
manual filling of the collection document), with a code of
bars in the Febraban pattern and sequentially numbered by the System
Path. This form of payment is similar to the form used for
document of collection of the National Simples (DAS).
Currently only the revenues under the administration of the
Shareholders' Equity (SPU) are being collected in Numbered Darf. In
soon other payments will also begin to be collected in this new
payment system.
Numbered Darf, like the DAS, can only be viewed
in the Sief System Collection Documents, not being possible,
consultation of this type of payment within the
Sign.
It is not possible to perform the rectification of Numbered Darf, taking into account
payment basis is recorded by the
issuing system of the document, and the taxpayer must inform
issuing body about a possible error in completing the document.
Source: link