How to categorize non-coding sequences in the genome?
Here's my likely over-simplified and incomplete categorization I could come up with. Please, for those more informed, please edit!

Noncoding sequences can be broken up into the following categories:

1. RNA genes (genes that produce tRNAs, rRNAs, miRNAs, etc.)
2. Introns and untranslated regions (UTRs)
3. Cis- and trans-regulatory elements
    3.1. Cis-regulatory elements (CREs)
        3.1.1. Promoters
        3.1.2. Enhancers
        3.1.3. Silencers
    3.2. Trans-regulatory elements (genes for transcription factors)
4. Repetitive elements (repeated sequences, repeats)
    4.1. Long terminal repeats (LTRs)
    4.2. Variable number tandem repeats (VNTRs, tandem repeats)
        4.2.1. Satellites
        4.2.2. Minisatellites
        4.2.3. Microsatellites (short tandem repeats, simple sequence repeats)
    4.3 Transposable elements (TEs, transposons)
        4.3.1. Retrotransposons (Class I TEs)
            4.3.1.1. Short interspersed nuclear elements (SINEs)
            4.3.1.2. Long interspersed nuclear elements (LINEs)
        4.3.2. DNA transposons (Class II TEs)
    4.4. Telomeres
5. Pseudogenes