You can use boolean logic (e.g. AND/OR/NOT) for complex search queries. For more help and examples, see the search documentation.

Search by package name:
my-package _(implicit)
name:my-package _(explicit)

Search by package filename:
my-package.ext _(implicit)
filename:my-package.ext _(explicit)

Search by package tag:
latest _(implicit)
tag:latest _(explicit)

Search by package version:
1.0.0 _(implicit)
version:1.0.0 _(explicit)
prerelease:true _{(prereleases)}
prerelease:false _{(no prereleases)}

Search by package architecture:
architecture:x86_64 

Search by package distribution:
distribution:el 

Search by package license:
license:MIT 

Search by package format:
format:deb 

Search by package status:
status:in_progress 

Search by package file checksum:
checksum:5afba 

Search by package security status:
severity:critical 

Search by package vulnerabilities:
vulnerabilities:>1 
vulnerabilities:<1000 

Search by package downloads:
downloads:>8 
downloads:<100 

Search by package type:
type:binary 
type:source 

Search by package size (bytes):
size:>50000 
size:<10000 

Search by dependency name/version:
dependency:log4j 
dependency:log4j=1.0.0 
dependency:log4j>1.0.0 

Search by uploaded date:
uploaded:>"1 day ago" 
uploaded:<"August 14, 2018 EST" 

Search by entitlement token (identifier):
entitlement:3lKPVJPosCsY 

Search queries for all Maven-specific (and related) package types

Search by group ID:
maven_group_id:org.apache 

Field type modifiers (depending on the type, you can influence behaviour)

For all queries, you can use:
~foo for negation

For string queries, you can use:
^foo to anchor to start of term
foo$ to anchor to end of term
foo*bar for fuzzy matching

For number/date or version queries, you can use:
>foo for values greater than
>=foo for values greater / equal
<foo for values less than
<=foo for values less / equal