Javadoc permits only a subset of HTML tags.
Javadoc’s doclint component enforces this restriction.
You can disable all doclint warnings by passing -Xdoclint:none to javadoc,
though you should consider fixing your Javadoc comments because otherwise the generated HTML API documentation may look bad or may omit content. (I usually use
-Xdoclint:all,-missing to get warnings about everything except missing Javadoc @ tags.)
I have not found public documentation of the tags that doclint permits, but here is a list of its allowed HTML tags, which I gleaned from the JDK’s file .../doclint/HtmlTag.java.
Java 17
A
ABBR
ACRONYM
ADDRESS
ARTICLE
ASIDE
B
BDI
BIG
BLOCKQUOTE
BODY
BR
CAPTION
CENTER
CITE
CODE
COL
DD
DEL
DFN
DIV
DT
EM
FONT
FIGURE
FIGCAPTION
FRAME
FRAMESET
H1
H2
H3
H4
H5
H6
HEAD
HR
HTML
I
IFRAME
IMG
INS
KBD
LI
LINK
MAIN
MARK
META
NAV
NOFRAMES
NOSCRIPT
P
Q
S
SAMP
SCRIPT
SECTION
SMALL
SPAN
STRIKE
STRONG
STYLE
SUB
SUP
TD
TEMPLATE
TH
TIME
TITLE
TT
U
UL
WBR
VAR
Java 8
A
B
BIG
BLOCKQUOTE
BODY
BR
CAPTION
CENTER
CITE
CODE
DD
DFN
DIV
DL
DT
EM
FONT
FRAME
FRAMESET
H1
H2
H3
H4
H5
H6
HEAD
HR
HTML
I
IMG
LI
LINK
MENU
META
NOFRAMES
NOSCRIPT
OL
P
PRE
SCRIPT
SMALL
SPAN
STRONG
SUB
SUP
TABLE
TBODY
TD
TFOOT
TH
THEAD
TITLE
TR
TT
U
UL
VAR
Java 9
JDK 9 permits a different set of tags than JDK 8 does. Here is a list of tags for both JDKs, with notes about those permitted by only one of the JDKs.
A
BIG // JDK 8 only
B // JDK 8 only
BLOCKQUOTE
BODY
BR
CAPTION
CENTER
CITE // JDK 8 only
CODE
DD
DFN // JDK 8 only
DIR // JDK 9 only
DIV
DL
DT
EM
FONT
FOOTER // JDK 9 only
FRAME // JDK 8 only
FRAMESET // JDK 8 only
H1
H2
H3
H4
H5
H6
HEAD
HEADER // JDK 9 only
HR
HTML
I
IFRAME // JDK 9 only
IMG
INPUT // JDK 9 only
LI
LINK
LISTING // JDK 9 only
MAIN // JDK 9 only
MENU
META
NAV // JDK 9 only
NOFRAMES // JDK 8 only
NOSCRIPT
OL
P
PRE
SCRIPT
SECTION // JDK 9 only
SMALL
SPAN
STRONG
SUB
SUP // JDK 8 only
TABLE
TBODY
TD
TFOOT // JDK 8 only
TH
THEAD // JDK 8 only
TITLE
TR
TT
U // JDK 8 only
UL
VAR // JDK 8 only