Changes

* Subset of OS specific: [https://bugzilla.mozilla.org/buglist.cgi?query_formato11=anywordssubstr&f13=CP&f1=OP&f3=short_desc&f4=short_desc&o5=substring&v4=os%20x&v3=%20macintosh%20Yosemite%20monterey%20Sierra%20Leopard%20lion%20%20catalina%20%20os-x%20macos%20Capitan%20mohave%20&o12=substring&f10=OP&f11=short_desc&f2=OP&f14=CP&v11=advancedmac%20osx%20mohave&product=MailNews+Core%20Core&product=Thunderbird&v5=mac%20os&o3=anywordssubstr&o4=substring&v12=mac&f5=short_desc&f12=op_sys&resolution=---&op_sysv6=Mac+System+7mac&op_sysquery_format=Mac+System+7.5advanced&op_sysj2=Mac+System+7.6.1OR&op_sysj10=Mac+System+8.0OR&op_sysf6=Mac+System+8.5short_desc&op_sysf7=Mac+System+8.6CP&op_syso9=Mac+System+9.xsubstring&op_syslist_id=Mac+OS+X15788382&chfieldtoo6=Nowanywords&field0-0-0v9=short_descos%20integration&type0-0-0bug_type=anywordsdefect&value0-0-0j1=mac+macintosh+osx+os-xOR&field0-0-1f8=short_descOP&type0-0-1f15=substringCP&value0-0-1f9=os+x component Mac], [https://bugzilla.mozilla.org/buglist.cgi?f6=short_desc&v6=windows%20win7%20win10&query_format=advanced&short_desc_typeresolution=anywords---&o9=substring&o8=substring&f7=CP&o6=anywordssubstr&list_id=15788374&f8=short_desc&f9=short_desc&bug_type=defect&v9=in%20windows&v8=on%20windows&o2=win32+substring&v3=windows%5Bwin2010&v1=windows7%5D+20windows10%5Bwindows20win32%5D+20win64%5Bw2k20win7%5D+windows+20win10%5Bw9820%5D+5Bwindows%5Bwin9820%5D+28windows%5Bwinme20%5D5Bwin&producto5=MailNews+Coreequals&productf3=Thunderbirdshort_desc&resolutionf4=---OP&op_sysf1=Windows+95short_desc&op_sysproduct=Windows+98Thunderbird&op_sysv2=Windows+MEwindows%207&op_sysj_top=Windows+NTOR&op_sysf2=Windows+2000short_desc&op_sysf5=Windows+XPcomponent&op_syso3=Windows+Server+2003substring&op_syso1=Windows+Vistaanywordssubstr&op_sysv5=Windows+7&op_sys=Windows+CE&op_sys=Windows+Mobile+6+Standard&op_sys=Windows+Mobile+6+Professional&chfieldto=Now os%20integration Windows], [https://bugzilla.mozilla.org/buglist.cgi?query_formatv4=advancedubuntu%20centos%20redhat%20&productf3=MailNews+Coreshort_desc&producto3=Thunderbirdregexp&resolution=---&op_sysv5=font%20color%20gtk%20window%20menu%20gnome%20kde%20lib&f7=LinuxCP&op_sysj2=Linux+%28embedded%29OR&chfieldtoquery_format=Nowadvanced&field0-0-0f8=short_descCP&type0-0-0product=regexpMailNews%20Core&value0-0-0product=.*ux+Thunderbird&field0-0-1f1=short_descOP&type0-0-1o4=anywordssubstr&value0-0-1f5=short_desc&o6=ubuntu+centos+redhat+regexp&field0-0-2f4=short_desc&type0-0-2v3=.%2Aux%20&o5=anywordssubstr&value0-0-2f6=short_desc&list_id=font+color+gtk+window+menu+gnome+kde+lib15788355&field0-0-3bug_type=short_descdefect&type0-0-3f2=regexpOP&value0-0-3op_sys=%5B+%5Dx.* Linux *ux] (may need adjusting to meet your needs)