use allow nil to avoid uniqueness validation when permalink not set on parameters
use allow nil to avoid uniqueness validation when permalink not set on parameters

magyarmosoly/akimasnakoktatas,stephenhack/yhacks,juanmanunez/catarse,stephenhack/yhacks,diraulo/catarse,paulopatto/catarse,Saharitte/catarse,sushant12/jvn,paulopatto/catarse,wlads/catarse,diraulo/catarse,thiagocatarse/catarse,rokibulhassan/catarse,coopsource/catarse,Haseeb-Qureshi/catarse,magyarmosoly/akimasnakoktatas,juanmanunez/catarse,gumanoz/catarse,nicolasiensen/bookstart,wlads/catarse,Haseeb-Qureshi/catarse,ujjwalkhanal/helpbegin,elesban/catarse,paulopatto/catarse,vicnicius/catarse,williamair1/catarse,liberland/catarse,thiagocatarse/catarse,JamesUcci/webapplication,catarse/catarse,umeshduggal/flockaway,gumanoz/catarse,devton/catarse,nicolasiensen/labcriativo,diegorv/catarse,coopsource/catarse,andrewyong82/100pp,thiagocatarse/catarse,ujjwalkhanal/helpbegin,ripple0328/catarse,vicnicius/catarse,paulodarosa/pollis.co,stephenhack/yhacks,rokibulhassan/catarse,mrmarcondes/catarse,danielweinmann/catarse,elesban/catarse,catarse/catarse,ripple0328/catarse,paulodarosa/catarse,paulodarosa/pollis.co,Saharitte/catarse,magyarmosoly/akimasnakoktatas,elesban/catarse,diegorv/catarse,ripple0328/catarse,diogob/catarse,umeshduggal/flockaway,nicolasiensen/labcriativo,globalavocado/catarse,umeshduggal/flockaway,victor95pc/catarse,mrmarcondes/catarse,catarse/catarse,andrewyong82/100pp,wlads/catarse,nicolasiensen/bookstart,vandofb/catarse,JamesUcci/webapplication,egozo/producerun,juanmanunez/catarse,sushant12/jvn,ujjwalkhanal/helpbegin,sushant12/jvn,victor95pc/catarse,adrianob/catarse,andrewyong82/100pp,diogob/catarse,globalavocado/catarse,vandofb/catarse,diraulo/catarse,JamesUcci/webapplication,adrianob/catarse,adrianob/99gamers,liberland/catarse,paulodarosa/catarse,diogob/catarse,mrmarcondes/catarse,egozo/producerun,williamair1/catarse,Haseeb-Qureshi/catarse,vandofb/catarse,liberland/catarse,devton/catarse,paulodarosa/catarse,nicolasiensen/labcriativo,devton/catarse,coopsource/catarse,globalavocado/catarse,diegorv/catarse,paulopatto/catarse,catarse/catarse,vicnicius/catarse,adrianob/catarse,danielweinmann/catarse,ujjwalkhanal/helpbegin,gumanoz/catarse,paulodarosa/pollis.co,adrianob/99gamers,egozo/producerun,sushant12/jvn,rokibulhassan/catarse,ripple0328/catarse,williamair1/catarse,victor95pc/catarse,devton/catarse,Saharitte/catarse,adrianob/99gamers