The referenced SVG file MAY be provided in GZIP-compressed [RFC1952]

form as an SVGZ file. In this case, the extension 'svgz' is used as

an alias for 'svg.gz' [RFC1952], i.e., octet streams of type

image/svg+xml, subsequently compressed with gzip as specified in

[SVGR]. The hash over the SVGZ file is calculated over the

decompressed SVG content with canonicalized EOL characters (<LF>) as

specified above.

When the SVG image is embedded using the "data" URL scheme as defined

in Section 4, SVG image data MUST be provided in SVGZ (GZIP

compressed) form (i.e., it MUST NOT be provided in uncompressed SVG

form).