jsp - How does Tomcat7 work with JSTL? Jar file name is important? -

i working on old system need use jsp , jstl. our tomcat version 7.0.29. using servlet 3.0 , jstl 1.2.

there strange behave. have download jstl-1.2.jar , renamed jar file jstl.jar (as our internal standard required). put web-inf/lib folder. when access jsp page, see below error:

the absolute uri: http://java.sun.com/jsp/jstl/core cannot resolved in either web.xml or jar files deployed application 

but, when renamed jstl.jar jstl-1.2.jar, restart tomcat, works fine. understanding, container scan jar files , find tld files under meta-inf folder. jar file name should not impact application.

is there know reason?