Original text:
Abstract In many IoT applications, direct discovery of resources is not <del> practical due to sleeping nodes, disperse networks, or networks where multicast traffic is inefficient.  These problems can be solved by employing an entity called a Resource Directory (RD), which contains information about resources held on other servers, allowing lookups to be performed for those resources.  The input to an RD is composed of links and the output is composed of links constructed from the information stored in the RD.  This document specifies the web interfaces that an RD supports for web servers to discover the RD and to register, maintain, lookup and remove information on resources. Furthermore, new target attributes useful in conjunction with an RD are defined. </del>  1. RFC6690 only describes how to discover resources from the web server that hosts them by querying "/.well-known/core".  In many constrained scenarios, direct discovery of resources is not practical due to <del> sleeping nodes, disperse networks, or networks where multicast traffic is inefficient.  These problems can be solved by employing an entity called a Resource Directory (RD), which contains information about resources held on other servers, allowing lookups to be performed for those resources. </del>  This document specifies the web interfaces that an RD supports for web servers to discover the RD and to register, maintain, lookup and RD replication: Point out that security policies may limit that.  changes from -24 to -25 Large rework of section 7 (Security policies)

Reviewer comments:
We were asked about the term in Erik's comments, and nobody could explain its relevance to the RD; removing it. See-Also: URL

Revised text:
Abstract In many IoT applications, direct discovery of resources is not  <ins> practical due to sleeping nodes, or networks where multicast traffic is inefficient.  These problems can be solved by employing an entity called a Resource Directory (RD), which contains information about resources held on other servers, allowing lookups to be performed for those resources.  The input to an RD is composed of links and the output is composed of links constructed from the information stored in the RD.  This document specifies the web interfaces that an RD supports for web servers to discover the RD and to register, maintain, lookup and remove information on resources.  Furthermore, new target attributes useful in conjunction with an RD are defined. </ins> 1. RFC6690 only describes how to discover resources from the web server that hosts them by querying "/.well-known/core".  In many constrained scenarios, direct discovery of resources is not practical due to  <ins> sleeping nodes, or networks where multicast traffic is inefficient. These problems can be solved by employing an entity called a Resource Directory (RD), which contains information about resources held on other servers, allowing lookups to be performed for those resources. </ins> This document specifies the web interfaces that an RD supports for web servers to discover the RD and to register, maintain, lookup and RD replication: Point out that security policies may limit that. <ins> Abstract, introduction: removed "or disperse networks" </ins> changes from -24 to -25 Large rework of section 7 (Security policies)