/usr/share/selinux/devel/policy.dtd is in selinux-policy-dev 2:2.20180114-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | <!ENTITY % inline.class "pre|p|ul|ol|li">
<!ELEMENT policy (layer+,(tunable|bool)*)>
<!ELEMENT layer (summary,module+)>
<!ATTLIST layer
name CDATA #REQUIRED>
<!ELEMENT module (summary,desc?,required?,(interface|template)*,(bool|tunable)*)>
<!ATTLIST module
name CDATA #REQUIRED
filename CDATA #REQUIRED>
<!ELEMENT required (#PCDATA)>
<!ATTLIST required
val (true|false) "false">
<!ELEMENT tunable (desc)>
<!ATTLIST tunable
name CDATA #REQUIRED
dftval CDATA #REQUIRED>
<!ELEMENT bool (desc)>
<!ATTLIST bool
name CDATA #REQUIRED
dftval CDATA #REQUIRED>
<!ELEMENT summary (#PCDATA)>
<!ELEMENT interface (summary,desc?,param+,infoflow?,(rolebase|rolecap)?)>
<!ATTLIST interface name CDATA #REQUIRED lineno CDATA #REQUIRED>
<!ELEMENT template (summary,desc?,param+,(rolebase|rolecap)?)>
<!ATTLIST template name CDATA #REQUIRED lineno CDATA #REQUIRED>
<!ELEMENT desc (#PCDATA|%inline.class;)*>
<!ELEMENT param (summary)>
<!ATTLIST param
name CDATA #REQUIRED
optional (true|false) "false"
unused (true|false) "false">
<!ELEMENT infoflow EMPTY>
<!ATTLIST infoflow
type CDATA #REQUIRED
weight CDATA #IMPLIED>
<!ELEMENT rolebase EMPTY>
<!ELEMENT rolecap EMPTY>
<!ATTLIST pre caption CDATA #IMPLIED>
<!ELEMENT p (#PCDATA|%inline.class;)*>
<!ELEMENT ul (li+)>
<!ELEMENT ol (li+)>
<!ELEMENT li (#PCDATA|%inline.class;)*>
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