The first thing to do here is Google the stock code and look at the company announcements.
You will very quickly see the following which explains what is occurring and the dates for which its occurring.
The ‘DA’ stands for deferred settlement so according to the announcement LYCDA will be in place till Dec 10th then normal trading under LYC will start on Dec 11th
http://www.asx.com.au//asxpdf/20171128/pdf/43pnx6txrz7j12.pdf