Explain regular expression
Explain regular expression

dreampet/gitlab,allysonbarros/gitlabhq,dwrensha/gitlabhq,openwide-java/gitlabhq,iiet/iiet-git,SVArago/gitlabhq,screenpages/gitlabhq,martijnvermaat/gitlabhq,jirutka/gitlabhq,icedwater/gitlabhq,allysonbarros/gitlabhq,stoplightio/gitlabhq,LUMC/gitlabhq,icedwater/gitlabhq,icedwater/gitlabhq,screenpages/gitlabhq,martijnvermaat/gitlabhq,daiyu/gitlab-zh,Soullivaneuh/gitlabhq,shinexiao/gitlabhq,htve/GitlabForChinese,daiyu/gitlab-zh,axilleas/gitlabhq,dwrensha/gitlabhq,htve/GitlabForChinese,dreampet/gitlab,shinexiao/gitlabhq,dplarson/gitlabhq,mr-dxdy/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,larryli/gitlabhq,LUMC/gitlabhq,LUMC/gitlabhq,daiyu/gitlab-zh,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,shinexiao/gitlabhq,htve/GitlabForChinese,icedwater/gitlabhq,screenpages/gitlabhq,Soullivaneuh/gitlabhq,t-zuehlsdorff/gitlabhq,htve/GitlabForChinese,shinexiao/gitlabhq,dreampet/gitlab,Soullivaneuh/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,Soullivaneuh/gitlabhq,darkrasid/gitlabhq,dplarson/gitlabhq,darkrasid/gitlabhq,dwrensha/gitlabhq,darkrasid/gitlabhq,iiet/iiet-git,larryli/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,openwide-java/gitlabhq,jirutka/gitlabhq,larryli/gitlabhq,screenpages/gitlabhq,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,SVArago/gitlabhq,dwrensha/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,daiyu/gitlab-zh,larryli/gitlabhq,mmkassem/gitlabhq,openwide-java/gitlabhq,darkrasid/gitlabhq,mr-dxdy/gitlabhq,openwide-java/gitlabhq,SVArago/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,SVArago/gitlabhq,dplarson/gitlabhq,jirutka/gitlabhq,axilleas/gitlabhq,martijnvermaat/gitlabhq,dplarson/gitlabhq,mr-dxdy/gitlabhq,mmkassem/gitlabhq,martijnvermaat/gitlabhq,allysonbarros/gitlabhq,LUMC/gitlabhq,allysonbarros/gitlabhq,mr-dxdy/gitlabhq