about the value of key "hl"(highlight) ,in solr 7.4

[魏北南]

Hello,


         I think    the value of the  key "hl"(highlight)    is incorrect ,,in 
solr 7.4;
         when I do some operations in UI,for example, query some key words and 
expect high light;and then I do, but I found some strange info from the log 
info:
*********************************************************************************************************************************
            2018-08-10 15:22:52.745 INFO  (qtp817348612-16) [   x:testcore] 
o.a.s.c.S.Request [testcore]  webapp=/solr path=/select 
params={q=goods_title:简介&hl=on&hl.simple.post=</span>&hl.fl=goods_title&hl.simple.pre=<span>&_=1533914503089}
 hits=1 status=0 QTime=284
*******************************************************************************************************************
         why is "h1=on"?why not "h1=true"?
        In fact ,"h1=on" can give me the expected response,"h1=true" not;
        I think above doesn't match with the Official documents
       
        
BRs
Wei Devin