The information about an entry that can not be described using FEATURES or the other fields. For instance, if submitter has the other affiliation to REFERENCE 1, it can be described on COMMENT line.

example
COMMENT     Human cDNA sequencing project.

"Structured COMMENT" for sampling in detail and genome data

To describe sample information in detail, COMMENT lines structured with sets of [item-name] and [item-value] can be used. This strategy is recommended to be used for submissions related to biodiversity and complete genome scale submissions.

example
COMMENT     ##Genome-Assembly-Data-START##
            Finishing Goal           :: Finished
            Current Finishing Status :: High Quality Draft
            Assembly Method          :: Newbler v. 2.3
            Genome Coverage          :: 30x
            Sequencing Technology    :: 454/Illumina
            ##Genome-Assembly-Data-END##

For MGA data

For MGA submissions. the process for obtaining the submitted sequence data e.g.; (methods for preparing sequences from tissues or cells and processing the sequences for submission) is described.

example
COMMENT     The CAGE (cap analysis gene expression) is based on preparation
            and sequencing of concatamers of DNA tags deriving from the
            initial 20/21 nucleotides from 5' end mRNAs.
            Full-length cDNAs were at first selected with the Cap-Trapper
            method. Then, a specific linker (Linker1, some linker contain 5 bp
            sequences that have 15 variations for each rna sample) containing
            the ClassIIs restriction enzyme site MmeI was then ligated to the
            single-strand cDNA and then the second strand of cDNA synthesized.
            The resulting double-stranded cDNA was cleaved by the restriction
            enzyme MmeI and a second linker (Linker2) was ligated to the 2 bp
            overhang at the MmeI cleaved site, to produce a 5' 20/21 tag
            having two linkers at both sides. The ligation products were
            separated from unmodified DNA with magnetic beads. The 5' end cDNA
            tags were released from the beads, and the DNA fragments were
            amplified in a PCR step by using the two linker-specific primers
            (Primer1 (uni-PCR), Primer2 (MmeI-PCR)). The desired 32-37 bp tags
            were purified and ligated to form concatamers, and then the
            concatamer were fractionated and ligated to the plasmid ZErO-2.
            The ligations were finally electroporated into DH10b cells
            (Invitrogen) and obtained plasmids were sequenced with forward
            primers.
            CAGE libraries were sequenced with forward primers essentially as
            described with minor modifications to use zeocin for selection of
            recombinants. We used in-house developed algorithms for the
            extraction of tags and for masking the vectors. CAGE tags were
            extracted with the following parameters: vector masking, minimum
            12 bp recognition allowed; linker (13 bp) masking: maximum
            mismatch, 2 bp allowed; XmaJI site maximum mismatch, 2 bp allowed;
            tag length, 17-24 bp.
            Linker1: "Upper oligonucleotide GN6":
            biotin-agagagagacctcgagtaactataacggtcctaaggtagcgacctagg (5 bp)
            tccgacGNNNNN and "Upper oligonucleotide N6":