is it the 'clipped off poly-A tail' and 'clipped off poly-A tail' right?

[Bianzh1024]

I download the transcriptome fasta from uscs, https://hgdownload.cse.ucsc.edu/goldenpath/mm9/bigZips/mrna.fa.gz . when I used kallisto index to bulid the index for kallisto, that had two warning:

[build] loading fasta file mrna.fa.gz
[build] k-mer length: 31
[build] warning: clipped off poly-A tail (longer than 10)
from 32479 target sequences
[build] warning: replaced 196300 non-ACGUT characters in the input sequence
with pseudorandom nucleotides
[build] counting k-mers ... done.
[build] building target de Bruijn graph ... done
[build] creating equivalence classes ... done
[build] target de Bruijn graph has 3001158 contigs and contains 263628489 k-mers

And it succeed. Why it showed the clipped and non-ACGUT ? The index is right?
I hope you can give me some advice. Thanks！ @pmelsted

[Yenaled]

Yes it’s fine