Somethins is not out of date.

Question

The document is out of date: PlantUML : Language Reference Guide, December 11, 2010 (Version 5737)

It is the doc I download from this website.
Page 11/96
Your code has changed.
It do not understand: the end tag :</size> ; </color> I jusr remove and it work; and the tag <strike>, it do not understand!.
Working code:

@startuml

participant Alice

participant "The <b>Famous </b> Bob" as Bob

Alice -> Bob : A <i>well formated </i> message

note right of Alice

This is <size:18>displayed 

<u>left of </u> Alice.

end note

note left of Bob

This is <color :#118888 > displayed 

<b><color:purple >left of Alice Bob </b>.

end note

note over Alice , Bob

This is hosted by <img:sourceforge.jpg >

end note

@enduml
Have a nice day!

Answer 1

Yes, the PDF document is out-of-date. Sorry about that... Someday, we will publish an updated version.

But the tags </size>, </color> and <strike> seem to be working.

See online:

http://www.plantuml.com/plantuml/form?url=JP113eCW44Ntd6BIhblZhZ5a4hle2Rm0wgYJeX30DEtf2sXDoII4p__p6AnoWJksQWbGQ-v8s3_br4m4iiM7citgGHOjmjsq9r0-xI8du995gA06oVWYhM4mRbQ1UbammapUgv74OWA1ut4AO8QTrapi8PRq_A6gl67FtchrJj4a8GYvegOXPsInOhG6nq_2t22wjfEWfOT4s32_H7hbmUYCDguwb-KjhdzIla0H9zqzTdLMqy7TKPijzKm_SJsGNm00

@startuml
participant Alice
participant "The <b>Famous </b> Bob" as Bob
Alice -> Bob : A <i>well formated</i> message
note right of Alice
This is <size:18>displayed</size>
<u>left of </u> <strike>Alice</strike>
end note
note left of Bob
This is <color:#118888>displayed</color>
<b><color:purple>left of Alice</color> Bob</b>.
end note
@enduml

Which version of PlantUML are you using ? Almost all versions should support </size> (maybe except very old one).
@startuml
version
@enduml

If you have a non-working example, thanks to post it here.

Regards,