RS (restart signal), is introduced into the Extended Options (EO) TLV in the Link-Local Signaling (LLS) block. 


LR stands for LSDB Resynchronization
https://tools.ietf.org/html/rfc4811#section-2.1

OSPF Link-Local Signaling

https://tools.ietf.org/html/rfc4813

2.4.1. Extended Options TLV

   This subsection describes a TLV called Extended Options (EO) TLV.
   The format of EO-TLV is shown in Figure 5.

   Bits in the Value field do not have any semantics from the point of
   view of the LLS mechanism.  This field may be used to announce some
   OSPF capabilities that are link-specific.  Also, other OSPF
   extensions may allocate bits in the bit vector to perform boolean
   link-local signaling.

   The length of the Value field in EO-TLV is 4 bytes.

   The value of the Type field in EO-TLV is 1.

   EO-TLV should only appear once in the LLS data block.

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |             1                 |           Length              |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                       Extended Options                        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 5: Format of EO-TLV

   Currently, [RFC4811] and [RFC4812] use bits in the Extended Options
   field of the EO-TLV.  The Extended Options bits are also defined in
   Section 5.